quinta-feira, 14 de fevereiro de 2008

Supernovas - Boletim Brasileiro de Astronomia - Ed. 447


SUPERNOVAS - BOLETIM BRASILEIRO DE ASTRONOMIA -
http://www.boletimsupernovas.com.br/

Quinta-feira, 07 de fevereiro de 2008 - Edicao No. 447

Indice:

_ ECLIPSE TOTAL DA LUA NO RJ
_ UFMG OFERECE CURSO DE INICIACAO 'A ASTRONOMIA
_ BOLETIM SUPERNOVAS TAMBEM DIVULGA ASTRONOMIA DURANTE CAMPUS PARTY
BRASIL 2008
_ ONU DECLARA 2009 O ANO INTERNACIONAL DA ASTRONOMIA
_ FENOMENO EM UMA NOVA E' EXPLICADO PELO MODO DE ANULACAO DO
INTERFEROMETRO KECK
_ ESTRELA HIPER-VELOZ DEMONSTRA SER ESTRANGEIRA
_ PROPOSTO TESTE PARA A TEORIA DAS CORDAS BASEADO NA ABSORCAO DO
HIDROGENIO NEUTRO
_ DECODIFICADO O AMBIENTE INTIMO DE UMA ESTRELA EM MATURACAO
_ RARA SUPERNOVA PODE REVELAR BURACOS NEGROS DE MASSA INTERMEDIARIA EM
AGLOMERADOS GLOBULARES
_ ESTRANHA PARCERIA NO ESCORPIAO
_ SONDANDO A TEIA DE ARANHA COSMICA DO UNIVERSO
_ SURPRESAS DESDE A SONDA MESSENGER
_ CASSINI ENCONTRA RITMO NOS ANEIS DE SATURNO
_ EVENTOS
_ EFEMERIDES PARA A SEMANA

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ASTRONOMIA NO BRASIL
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ECLIPSE TOTAL DA LUA NO RJ
03/02/2008. Na noite de 20 para 21 de fevereiro, a Fundacao Planetario
vai abrir as portas ao publico para acompanhar o eclipse total da Lua.
O inicio do eclipse acontecera' `as 22h43. O apice do fenomeno
ocorrera' `a 0h26, com termino `as 2h9. Os visitantes serao recebidos
na Praca dos Telescopios e a atividade tera' o acompanhamento dos
astronomos da instituicao que estarao ao dispor para esclarecer
duvidas e conversar sobre os astros e outros fenomenos astronomicos.
Distribuicao de 260 senhas a partir das 22h. A atividade dependera'
das condicoes meteorologicas. Com o tempo nublado ou chuvoso, nao e'
possivel a observacao. Fundacao Planetario da Cidade do Rio de
Janeiro Rua Vice-Governador Rubens Berardo, 100 - Gavea Tel: 2274-0046
- Rio de Janeiro, RJ. Site:
http://www.rio.rj.gov.br/planetario/
Ed: CE

UFMG OFERECE CURSO DE INICIACAO 'A ASTRONOMIA
28/01/2008. Movimentos de estrelas e planetas, uso de cartas celestes,
eclipses e a estrutura do universo sao alguns dos temas do Curso de
Iniciacao `a Astronomia, que o departamento de Fisica do Instituto de
Ciencias Exatas (ICEx) da UFMG promove de 11 a 16 de fevereiro. O
curso sera' ministrado por professores do Observatorio Astronomico
Frei Rosario, da Universidade, e tera' aulas teoricas, apoiadas por
recursos multimidia (no campus Pampulha), e praticas, com o uso de
cartas celestes, binoculos e telescopios (no Observatorio, que fica na
Serra da Piedade). A taxa cobrada e' de R$ 220,00 `a vista), com
opcao de tres pagamentos de R$ 80,00. Estao previstos descontos para
grupos de colegio ou familias. Informacoes estao disponiveis no
Observatorio, pelo telefone (31) 3409-5679 e pelo endereco
astrovis@fisica.ufmg.br; e no Cenex/Fisica, pelo telefone (31)
3409-5634 e pelo endereco
idalina@fisica.ufmg.br. As inscricoes podem
ser feitas nos escritorios da Fundep localizados no Conservatorio UFMG
(avenida Afonso Pena 1.534) e na loja 7 da Praca de Servicos do campus
Pampulha (avenida Antonio 6.627).
Ed: CE

BOLETIM SUPERNOVAS TAMBEM DIVULGA ASTRONOMIA DURANTE CAMPUS PARTY
BRASIL 2008
07/02/2008. Esta' prestes a comecar o maior evento de tecnologia e
internet do Brasil, a Campus Party Brasil, de 11 a 17 de fevereiro. O
evento que acontece desde 1997 na Espanha, sera' realizado pela
primeira vez Brasil na cidade de Sao Paulo, e espera reunir 3
inscritos e cerca de 30 mil visitantes. Diversas areas de interesse
irao girar em torno de varios eixos tematicos, como Criacao,
Desenvolvimento, Simulacao, Robotica, Games, Software Livre e outros.
A Astronomia nao ficara' de fora e promete ser um dos temas mais
atraentes. Durante os seis dias havera' uma programacao especial com
oficinas de astrofotografia, competicoes, foruns e conferencias com
nomes importantes na area, como Marcos Pontes, Walmir Cardoso, Jose'
Carlos Diniz, Augusto Daminelli, Naelton Araujo, Paulo Pedrosa, Joao
Paulo Delicato, Cristovao Jaques, Tasso Napoleao, entre outros. O
fisico Roberto de Andrade Martins explicara' como a pesquisa e
desenvolvimento tecnologico contribuem com a astronomia. "A
expectativa e' muito grande. Teremos um evento sensacional, onde vamos
poder falar, ouvir e praticar astronomia durante toda a semana", disse
Walmir Cardoso, coordenador da area. O Boletim Supernovas tambem
marcara' presenca com um forum de comunicacao na internet, conversando
sobre a divulgacao da astronomia na internet durante os 8 anos do
boletim. A Campus Party Brasil vai contar tambem com o apoio do
Planetario de Sao Paulo, Sociedade Brasileira para o Ensino da
Astronomia (SBEA) e Clube de Astronomia de Sao Paulo (CASP), que
programou observacoes noturnas e diurnas do ceu durante o acampamento.
Mais informacoes e a programacao completa no site do evento:
http://www.campus-party.com.br
Ed: CE

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ASTRONOMIA NO MUNDO
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ONU DECLARA 2009 O ANO INTERNACIONAL DA ASTRONOMIA
07/02/2008. Em dezembro de 2007, a 62ª Assembleia da Organizacao das
Nacoes Unidas proclamou 2009 como o Ano Internacional da Astronomia. A
resolucao foi submetida pela Italia, patria de Galileu Galilei, e teve
completo apoio do Segundo Comite' da Assembleia Geral. O Ano
Internacional da Astronomia e' uma iniciativa da Uniao Astronomica
Internacional e da UNESCO. Com o Ano Internacional da Astronomia 2009
(IYA2009) nos celebramos um evento especial: o primeiro uso
astronomico de um telescopio por Galileu Galilei – uma invencao que
desencadeou 400 anos de incriveis descobertas astronomicas. A isso se
seguiu uma revolucao cientifica que alterou profundamente nossa visao
de mundo. Hoje, telescopios em solo e em orbita exploram o Universo 24
horas por dia, em todos os comprimentos de onda do espectro
eletromagnetico. A presidente da IAU, Catherine Cesarsky, diz: "O Ano
Internacional da Astronomia 2009 da' a todas as nacoes a chance de
participar nesta excitante revolucao cientifica e tecnologica em
curso." O IYA2009 e' uma colaboracao global para fins pacificos – a
procura de nossas origens cosmicas, uma heranca compartilhada por
todos os cidadaos do planeta Terra. A ciencia da Astronomia representa
milenios de colaboracoes atraves das fronteiras: geograficas, idades e
generos, racas e culturas, fornecendo uma base completa para a Carta
de Principios da ONU. Neste sentido, a Astronomia e' um exemplo
classico de como a ciencia pode contribuir para o aprofundamento da
colaboracao internacional. O assim chamado Ponto de Contato
Brasileiro, Augusto Damineli, explica: "A rede Brasileira do IYA 2009
oferecera' uma ampla lista de atividades ja' a partir de 2008, que
pode ser vista em
http://www.astronomia2009.org.br/. Entre nossos
objetivos, ofereceremos a pelo menos 1 milhao de pessoas a
oportunidade de ver o ceu atraves de telescopios. Outro objetivo e' o
de difundir na sociedade uma mentalidade cientifica. Isto e' essencial
para os cidadao agirem num mundo permeado pela tecnologia e carente de
planejamento global de recursos." Historico: Durante a Assembleia
Geral da IAU em 23 de Julho de 2003 em Sydney (Australia), foi
aprovado por unanimidade a resolucao em favor da proclamacao de 2009
como o Ano Internacional da Astronomia. Baseados na iniciativa da
Italia, a Conferencia Geral da UNESCO em sua 33ª sessao recomendou `a
ONU que adotasse a resolucao de declarar o 2009 como o Ano
Internacional da Astronomia. Finalmente, a 62ª Assembleia da ONU
designou a UNESCO como sendo a agencia para liderar o IYA2009. A IAU
implementara' o IYA2009 atraves de uma rede mundial. Dela ja'
participam 93 paises, coordenando esforcos de astronomos
profissionais, amadores, educadores e artistas. O IYA2009 e', em
primeiro lugar, uma atividade para o cidadao de todo o planeta Terra.
Ele objetiva combinar a excitacao da descoberta pessoal, o prazer de
compartilhar conhecimentos fundamentais sobre o Universo e nosso lugar
nele, com os meritos do metodo cientifico. O poder de inspiracao da
Astronomia representa um valioso recurso para a especie humana e para
todas as nacoes. A visao do IYA2009 e' de ajudar os cidadaos de todo
mundo a descobrir seu lugar no Universo atraves do ceu diurno e
noturno e, portanto produzir um sentimento de maravilha e descoberta.
Todos os humanos deveriam perceber o impacto da Astronomia e outras
ciencias basicas em seu cotidiano e entender melhor como o
conhecimento cientifico pode contribuir para uma sociedade mais justa
e pacifica. O objetivo do IYA2009 e' o de estimular em todo o mundo,
especialmente entre os jovens, o interesse pela Astronomia e outras
ciencias sob o tema central: O Universo para voce' descobrir. As
atividades do IYA2009 serao a nivel mundial e regional (especialmente
a nivel nacional e local). Centenas de "nos" locais estao se formando
em todo o Brasil, para preparar as atividades de 2009. Esses "nos"
contam com a colaboracao de astronomos profissionais, amadores,
centros de ciencia, planetarios, educadores e artistas. A IAU e' a
organizacao internacional que congrega cerca de 10 mil ilustres
astronomos de todas as nacoes do mundo. Fundada em 1919, a IAU e' a
maior organizacao de astronomos profissionais. Sua missao e' promover
a Astronomia em todos os seus aspectos, atraves de cooperacao
internacional. Sua Assembleia Geral de 2009 sera' realizada no Rio de
Janeiro como forma de sinalizar o interesse mundial despertado pelo
vigoroso crescimento da Astronomia Brasileira. Para maiores
informacoes contate:
iya2009@astro.iag.usp.br ou na homepage:
www.astronomia2009.org.br ( Fonte: Adaptado. Vera Aparecida Fernandes
Martin, Universidade Estadual de Feira de Santana )
Ed: CE

FENOMENO EM UMA NOVA E' EXPLICADO PELO MODO DE ANULACAO DO
INTERFEROMETRO KECK
28/01/2008. Os primeiros resultados de um novo instrumento cientifico
do Observatorio W. M. Keck ajudam os cientistas a entenderem a fisica
de uma nova recorrente, um tipo de sistema estelar cataclismico. Os
resultados estao contrariando suposicoes estabelecidas por muito tempo
sobre as poderosas explosoes denominadas novas e produziram o primeiro
modelo unificado para uma nova recorrente chamada de RS Ophiuchi. (
Fonte:
http://www.keckobservatory.org/article.php?id=190 )
Ed: JG

ESTRELA HIPER-VELOZ DEMONSTRA SER ESTRANGEIRA
28/01/2008. Uma estrela jovem esta' fugindo velozmente da Via Lactea,
tao rapido que os astronomos ficaram desconcertados sobre onde ela
provem. Baseado na sua curta idade, tem viajado longe demais para
provir da nossa galaxia. Agora, por meio da analise da sua velocidade,
da intensidade da sua luz e, pela primeira vez, da sua historia
relatada pelos elementos quimicos que a compoe, os astronomos da
Instituicao Carnegie, Alceste Bonanos e Mercedes Lopez-Morales, e seus
colaboradores, Ian Hunter y Robert Ryans, da Universidade da Rainha,
de Belfast, determinaram que ela provem da nossa galaxia vizinha, a
Grande Nuvem de Magalhaes. O resultado indica que foi expulsa dessa
galaxia por um buraco negro massivo ainda nao observado. A pesquisa
sera' publicada num proximo numero do Astrophysical Journal Letters. (
Fonte:
http://www.ciw.edu/news/hyperfast_star_proven_be_alien )
Ed: JG

PROPOSTO TESTE PARA A TEORIA DAS CORDAS BASEADO NA ABSORCAO DO
HIDROGENIO NEUTRO
28/01/2008. A antiga luz absorvida pelos atomos de hidrogenio neutro
pode ser utilizada para testar algumas das predicoes da teoria das
cordas, dizem os cosmologistas da Universidade do Illinois. Fazer as
medicoes, porem, requer um gigantesco conjunto de radiotelescopios que
deverao ser construidos na Terra, no espaco ou na Lua. ( Fonte:
http://www.news.uiuc.edu/news/08/0128string.html )
Ed: JG

DECODIFICADO O AMBIENTE INTIMO DE UMA ESTRELA EM MATURACAO
29/01/2008. Usando o Interferometro VLT da organizacao Observatorio
Europeu Austral (ESO), os astronomos sondaram o interior do disco de
material que rodeia um jovem objeto estrelar, percebendo a forma em
que ele ganha massa antes de virar adulto. Os astronomos tinham
realizado uma outra observacao do objeto conhecido como MWC 147,
situado a 2600 anos-luz da Terra na direcao da constelacao de
Monoceros, o Unicornio. MWC 147 pertence `a familia de objetos Herbig
Ae/Be. Esses objetos tem poucas massas solares e ainda estao se
formando, aumentando a sua massa pela absorcao do material presente no
disco que os rodeia. ( Fonte:
http://www.eso.org/public/outreach/press-rel/pr-2008/pr-03-08.html )
Ed: JG

RARA SUPERNOVA PODE REVELAR BURACOS NEGROS DE MASSA INTERMEDIARIA EM
AGLOMERADOS GLOBULARES
29/01/2008. Estranho e violento destino espera uma ana' branca que
passa perto demais de um buraco negro moderadamente massivo. Segundo
novo estudo, o puxe gravitacional do buraco negro sobre a ana' branca
poderia causar forcas de mare' suficientes para destrocar o
remanescente estelar e reiniciar a ignicao nuclear nela, dando lugar a
uma explosao de supernova com aparencia rara. Observacoes dessas
supernovas podem confirmar a existencia de buracos negros de massa
intermediaria, atualmente tema de debate entre os astronomos. ( Fonte:
http://www.ucsc.edu/news_events/text.asp?pid=1903 )
Ed: JG

ESTRANHA PARCERIA NO ESCORPIAO
30/01/2008. E' a primeira vez que se observa um objeto celeste tao
pouco massivo em orbita a grande distancia de uma ana' marrom. Ele tem
14 vezes a massa de Jupiter e se desloca ao redor de uma ana' marrom
que se acha a uma distancia 700 vezes maior que a que separa a Terra
do Sol. Com sua verdadeira natureza ainda por determinar, o
companheiro, de massa planetaria, denominado UScoCTIO108B e a parceria
com sua ana' marrom protagonizam a descoberta, na constelacao do
Escorpiao, realizada por cientistas do Instituto de Astrofisica de
Canarias (IAC) e da Universidade Politecnica de Cartagena. ( Fonte:
http://www.iac.es/divulgacion.php?op1=16&id=513 )
Ed: JG

SONDANDO A TEIA DE ARANHA COSMICA DO UNIVERSO
30/01/2008. Utilizado o telescopio VLT da organizacao Observatorio
Europeu Austral (ESO), uma equipe de astronomos foi capaz de medir a
distribuicao e movimentos de milhares de galaxias no Universo
distante. Isso abre fascinantes perspectivas para compreender melhor a
causa da aceleracao na expansao cosmica e melhora o entendimento da
misteriosa energia escura que presumivelmente esta' em todo o
Universo. ( Fonte:
http://www.eso.org/public/outreach/press-rel/pr-2008/pr-04-08.html )
Ed: JG

SURPRESAS DESDE A SONDA MESSENGER
30/01/2008. Apos uma viajem de mais de 3,5 bilhoes de quilometros de 3
anos e meio de duracao, a sonda MESSENGER da NASA realizou o seu
primeiro sobrevoo de Mercurio, em 14 de janeiro de 2008. Os sete
instrumentos cientificos que leva a bordo funcionaram perfeitamente,
produzindo surpresas que estao deleitando os cientistas da missao. As
1213 imagens enviadas mostram que o planeta e' bem menos parecido com
a Lua do que muitos achavam, mostrando caracteristicas unicas desse
planeta. A complexa magnetosfera parece ser bem diferente da observada
pela sonda Mariner 10, ha' 34 anos. ( Fonte:
http://www.jhuapl.edu/newscenter/pressreleases/2008/080130.asp )
Ed: JG

CASSINI ENCONTRA RITMO NOS ANEIS DE SATURNO
31/01/2008. A sonda Cassini, da NASA, descobriu que dois dos aneis de
Saturno contem linhas ordenadas de grupos densos de particulas geladas
que se estendem ao longo dos aneis como as ondas formadas pela queda
de uma pedra num lago calmo. "Imagine ir atravessando uma cidade e
observar edificios espacados a igual distancia em cada quarteirao",
menciona Essam Marouf, da Universidade do Estado de Sao Jose'. "Todos
esses grupos de particulas nos aneis encontram-se muito perto, e o
espaco entre eles e' extremamente pequeno, de 100 a 250 metros,
dependendo de onde se encontram no anel". ( Fonte:
http://www.jpl.nasa.gov/news/features.cfm?feature=1594 )
Ed: JG

----------------------------------------------------------
EVENTOS
----------------------------------------------------------

04/01/2008 a 20/02/2008 - Bolsa para jovens doutores em Cosmologia e
areas afins: O Instituto de Cosmologia, Relatividade e Astrofisica do
Centro Brasileiro de Pesquisas Fisicas (ICRA/CBPF) abriu processo de
selecao para preenchimento de uma vaga de pesquisador visitante pelo
periodo de seis meses, a contar de 2 de abril. O processo de selecao
levara' em conta a atividade cientifica dos candidatos nos ultimos 5
(cinco) anos, bem como sua atuacao, preferencialmente nas areas de
Cosmologia (teoria e fenomenologia), teoria da gravitacao, teoria de
campos em espacos curvos e astrofisica relativista. Os candidatos
deverao encaminhar, ate' o dia 20 de fevereiro, carta dirigida ao
presidente do Comite' Cientifico do ICRA, professor Mario Novello,
manifestando interesse em participar do Processo, acompanhada de
curriculo e projeto de trabalho para o periodo. Os enderecos postal e
eletronico para envio desses documentos sao: Bolsa Pesquisador
Visitante 2008 - ICRA/CBPF - Rua Dr Xavier Sigaud, 150 - Urca
22290-180 - Rio de Janeiro, ou
dayse@cbpf.br. ( Fonte: JC )
Ed: CE

11/02/2008 a 17/02/2008 - CAMPUS PARTY BRASIL: A area de Astronomia e'
uma das mais atraentes da Campus Party Brasil. O estudo das
constelacoes e luas, o contato com telescopios e a astrofotografia,
sao alguns dos temas que vao compor as diversas atividades previstas
para este segmento. A Campus Party Brasil vai contar tambem com o
apoio do Planetario de Sao Paulo, que proporcionara' aos participantes
todo o prazer de observacoes noturnas e diurnas do ceu.
http://www.campus-party.com.br//index.php3
Ed: CE

20/02/2008 a 20/02/2008 - OBSERVACAO ASTRONOMICA EM BAURU: O
Observatorio Astronomico da UNESP/Bauru esta' programando uma noite
especial de observacoes astronomicas em 20 de fevereiro de 2008,
quando teremos um eclipse total da Lua. Saturno tambem sera' o alvo da
noite. O evento, que faz parte da programacao do IAY2009 e promovido
pelo GEDAI (Grupo de Educacao e Divulgacao para a Astronomia
Interdisciplinar), tera' inicio `as 21h00min no IPMET/OBSERVATORIO da
UNESP de Bauru (SP), com uma breve explicacao inicial sobre o
fenomeno, sendo aberto ao publico interessado. Teremos telescopios
disponiveis, mas aqueles que desejarem trazer seus equipamentos
(lunetas, binoculos, cameras fotograficas) poderao incrementar a festa
celeste. Para maiores detalhes, contate a Profa. Dra. Rosa Scalvi
(Depto. Fisica-UNESP), no e-mail:
rosama@fc.unesp.br ou Rodolfo
Langhi, no e-mail:
rlanghi@fc.unesp.br ( Fonte: Rodolfo Langhi )
Ed: CE

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EFEMERIDES PARA A SEMANA
----------------------------------------------------------
07/02/2008 a 16/02/2008
Efemerides dia-a-dia
Ed: RG

7 Fevereiro
Lancamento: Progress M-63 Soys U (International Space Station 28P)
Ano Novo Chines
Inicio da Fase de Eclipse Umbral 01:19
Lua Nova 01:44
Maximo Eclipse Solar Anular, visivel da Antartica 01:55
Final da Umbral do eclipse solar anular 02:30
Final do Eclipse solar anular 04:11
Cometa P/2000 U6 Tichy em perielio a 2.138 UA do Sol 05?07
Luz Zodiacal sobre o horizonte ES 05:07

8 Fevereiro
Sonda Cassini sobrevoo distante a Epimetheus, Pandora e Atlas
Asteroide 2007 SP11 passa a 0.091 UA das Terra
Luz Zodiacal sobre o horizonte ES 05:07
Mercurio mais proximo da Terra 0.649UA 14:06

9 Fevereiro
Luz Zodiacal sobre o horizonte ES 05:07
Chuveiro de Meteoros beta Centaurideos em maxima atividade, THZ=13.1
em Centauro 15:00
Lua, Luz cinerea 20:02

10 Fevereiro
Asteroide 2006 DU62 passa a 0.055 UA da Terra
Luz Zodiacal sobre o horizonte ES 05:08
Lua. Luz Cinerea 20:07

11 Fevereiro
Asteroide 2007 RV9 passa a 0.077 UA da Terra
Asteroide 2007 CS5 Passa a 0.082 da Terra
Netuno em Conjuncao com o Sol
Io, 5.9 mag, Inicio de Eclipse 04:54
Luz Zodiacal sobre o horizonte ES 05:08
Lua. Luz Cinerea 20:07

12 Fevereiro
Asteroide 2007 Da passa a 0.025 UA da Terra
Io, 5.9mag, Final de Sombra 04:16
Io, Final de Transito 05:06
Luz Zodiacal sobre o horizonte ES 05:08
Lua. Luz Cinerea 20:07

13 Fevereiro
Cometa C/2007 T5 Gibbs em Perielio a 4.408 do Sol
Luz Zodiacal sobre o horizonte ES 05:08
Lua. Luz Cinerea 20:07
Chuveiro de Meteoros Leonideos, ativo ate' 25/04 22:00
Lua em Perigeu a 370256.0 km da Terra 22:56

14 Fevereiro
Lancamento: STS-123, Space Shuttle Endeavour, Japan's ELM-PS, Canadian
Hand "Dextre" (International Space Station 1J/A)
Cometa C/2007 T1 McNaught passa a 1.064 UA da Terra
Lua Quarto Crescente 01:33
Europa, 6.5mag, Inicio de Eclipse 05:41
Luz Zodiacal sobre o horizonte ES 05:08
Lua em Libracao Sul 06:38

15 Fevereiro
Asteroide 162567 (2000 RW37) PASSA A 0.072 ua DA tERRA
Lua, Imersao da estrela Phi Tau, SAO 76558, 5.0mag na borda escura
lunar 01:46
Ganymed, 5.5mag, Final de Sombra 04:02
Ganymed, Inicio de Transito 04:40
Luz Zodiacal sobre o horizonte ES 05:08

16 Fevereiro
Lua, Imersao da estrela Alnath, beta Tau, 1.6mag na borda escura lunar
01:46
Lua e Marte, -0.2mag, separados a 3.7 graus 01:08
Lua, Maxima Declinacao Norte 04:09
Europa, 6.5mag, Final de Transito 05:17
Luz Zodiacal sobre o horizonte ES 05:08

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GLOSSARIO
----------------------------------------------------------

Os verbetes deste Glossario foram extraidos do Astro.dic -
Dicionario de Astronomia e Areas Afins, que disponibiliza todo seu
conteudo no Site:
http://www.ceaal.al.org.br/astrodic/
Ed: LL

----------------------------------------------------------
Supernovas - Boletim Brasileiro de Astronomia, e' uma publicacao
semanal em forma de boletim eletronico, via e-mail, estruturado em
diferentes Editorias e elaborado pela comunidade astronomica
profissional e amadora brasileira com o objetivo de ampliar a
divulgacao de informacoes sobre a Astronomia no Brasil e no mundo.
Semanalmente, ele e' enviado a aproximadamente 10000 interessados.
Informacoes gerais sobre Astronomia e Ciencias afins podem ser
encontradas no site do Boletim na Internet, no endereco:
http://www.boletimsupernovas.com.br/
Para receber semanalmente o Boletim, envie um e-mail para
<
boletimsupernovas-subscribe@yahoogroups.com> e para deixar de
assina-lo envie um e-mail para
<
boletimsupernovas-unsubscribe@yahoogroups.com>. Nao e' necessaria
nenhuma informacao no corpo desses e-mails.
Devido a limitacoes de diversos provedores de e-mails, a acentuacao
grafica das edicoes sao omitidas.
Informacoes, sugestoes e criticas podem ser encaminhadas aos
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domingo, 10 de fevereiro de 2008

Alineamiento Venus y Jupiter/Secuencia conjunción y fin del Ocultamiento a la Estrella Nunki (mag.2.2)

Venus y Júpiter se alinearon (estuvieron casi coincidentes en la linea de visión, apenas 36’30”) el pasado 1 de febrero. Cuando lentamente se iban separando, el día 4, recibieron la visita de la Luna, ocasionando un notable espectáculo celeste que fue observado por muchas personas.
Algunos aprovecharon para tomar fotografías. He visto varias, pero quizás las más interesantes sean una secuencia de imágenes captadas por el Ing. Gustavo Ferreira Rojas y que me fueron enviadas por el Prof. Miguel Volpe, del Club de Astrofísica del Paraguay.
Lastimosamente, no cuento con información sobre los instrumentos usados para tomar las fotografías ni sobre el lugar ni la hora exactos. Supongo que las fotos fueron captadas con una cámara digital común, en Asunción o en sus cercanías y que el horario impreso automáticamente por la cámara es aproximado al horario exacto.
A continuación la secuencia fotográfica. Es recomendable observar cada imagen con detenimiento y atención.

Haz clic en las imagenes para amplialas

Júpiter aparece arriba a la izquierda (magnitud = –1.9 y diámetro aparente = 32.7”), Venus hacia abajo (m = -3.9; d = 12.4”), la Luna a la derecha (m = -6.97; d = 30.5’).




Aparentemente se ha dado mayor tiempo de exposición a las imágenes a partir de ésta. Se puede observar algunas estrellas cerca de Venus. Se puede observar también los “mares” en la parte oscura de la Luna; esa región no recibe luz directa del Sol sino reflejada por la Tierra.


Al final de la secuencia esta fotografía ha sido reproducida incluyendo números cerca de las estrellas para poder identificarlas.
Se puede observar en esta imagen un débil arco abajo y hacia la derecha de Venus (abajo y a la izquierda en la imagen de las 05:47). Posiblemente sea un reflejo del arco iluminado de la Luna que es muy brillante. El arco es visible en diversas posiciones en varias de las fotografías que siguen.





¡Sorpresa! ¡Una estrella está emergiendo detrás de la luna! Esto se confirma en las siguientes imágenes.








Fin de la secuencia.



Venus: m = -1.9 diam = 32.7” fracción iluminada: 0.997

Júpiter: m = -3.9 diam = 12.4” fracción iluminada: 0.853

Luna: m = -6.97 diam = 30.5’ fracción iluminada: 0.082

1 - (xi) 1 Sagittarii m = 5.08

2 - 2 Sgr m = 3.51

3 - (omicron) Sgr m = 1.38 .. 1.51 estrella variable

4 - (nu) 2 Sgr m = 4.99

5 - 1 Sgr m = 4.90/10.80 estrella doble

6 - (phi) Sgr m = 3.17

(Oculta) (sigma) Sgr m = 2.02


En el cielo ocurren muchas cosas, es cuestión de sentarse a observar.

Oscar Herreros Usher, M. Sc
Ciudad del Este, 8 de Febrero de 2008




Posted by:
Lucimary Vargas
Presidente
Observatório Monoceros
Além Paraíba-MG-Brasil

Venus-Jupiter con la Luna y Antares - 01 feb 2008

Haz clic

Luna en Escorpio - 01 feb 2008

Haz clic

Conjunción Venus e Jupiter - 01 feb 2008

Haz clic en las imagenes para amplialas






Conjunción Venus e Jupiter - 01 feb 2008

Haz clic en las imagenes para amplialas






sábado, 9 de fevereiro de 2008

Astronomia.com - Newsletter 8 febbraio 2008

Caro appassionato/a,
come ogni settimana Astronomia.com Ti informa sulle ultime pubblicazioni:

Fuga dalla GRande Nube (7 febbraio) - di Claudio Elidoro
La composizione chimica della stella HE 0437-5439 indica con chiarezza che questa hypervelocity star si è formata nella Grande Nube di Magellano.
News completa: http://www.astronomia.com/2008/02/07/fuga-dalla-grande-nube/

Nuove tempeste su Giove (5 febbraio) - di Claudio Elidoro
Osservata la comparsa di due gigantesche tempeste nell'atmosfera di Giove la cui origine va ricercata nella complessa termodinamica che governa gli strati atmosferici più profondi.
News completa: http://www.astronomia.com/2008/02/05/nuove-tempeste-su-giove/

I pianeti gassosi minori: Urano e Nettuno (4 febbraio) - di Pierluigi Panunzi
Siamo quasi arrivati ai confini del Sistema Solare. Scopriamo insieme Urano e Nettuno, i pianeti che nell'ultimo ventennio sono stati raggiunti e studiati più approfonditamente dalle sonde spaziali.
Articolo completo: http://www.astronomia.com/2008/02/04/i-pianeti-gassosi-minori-urano-e-nettuno/

Ombre su Marte (3 febbraio) - di Claudio Elidoro
Lo strumento OMEGA rileva sulla superficie del Pianeta rosso le ombre proiettate da dense nubi di anidride carbonica.
News completa: http://www.astronomia.com/2008/02/03/ombre-su-marte/

Prova i nostri feed RSS! http://www.astronomia.com/feed/

Appuntamento alla prossima settimana!
Lo staff di Astronomia.com
 
 
Posted by:
Lucimary Vargas
Além Paraíba-MG-Brasil
observatorio.monoceros@gmail.com

quarta-feira, 6 de fevereiro de 2008

Space cargo ship near completion

 

 
By Jonathan Amos
Science reporter, BBC News
Fuelling suits for ATV (Esa/Cnes/Arianespace)
The last fuelling procedure begins on Friday morning
The launch and docking windows for the ATV, Europe's huge new space-station resupply ship, have been set.

The Automated Transfer Vehicle (ATV) will be lofted in the 22 February to 8-9 March timeframe, European Space Agency (Esa) officials say.

The 20-tonne vessel will then attach itself to the international outpost during one of two windows; in early March, or in late March to early April.

ATV is the biggest, most sophisticated spacecraft Europe has attempted to fly.

Its preparation at the Kourou spaceport in French Guiana is very nearly complete.

This Friday, engineers will start the final stage of fuelling, adding 2.7 tonnes of oxidiser to the ship's propellant system.

Once this is done, and major headway has been made on the final 200 or so items on an "open work list", the ATV will be moved out of Kourou's giant S5 integration halls and taken to the Baf (Final Assembly Building) where it will be mated with its Ariane 5 launcher.

SPACE STATION CARGO TRUCKS
Comparison of ATV and Progress
ATV (l) will resupply the ISS with up to 7,500kg of cargo
Capacity is three times that of the Russian Progress craft (r)
Deliveries will include science equipment, food and clothing
Large tanks can transport vital air, water and fuel supplies
ATV project's estimated cost is about 1.3bn euros (£0.9bn)
At least four craft will follow the maiden ATV - Jules Verne
Named after the author who wrote about fantastic journeys

 
"We are on schedule," said Nicolas Chamussy, ATV programme manager for prime contractor EADS Astrium.

"Since October, we have lost just three days in the planning. We have some 200 actions still to do, but these are normal; I don't see major issues," he told BBC News.

Last week, at a general designers' review in Moscow, the Russians (one of the major partners in the space station project) gave their formal approval for the mission to proceed. A similar meeting will be held in the US this week at which the Americans are also expected to sign off ATV.

A gathering of space agency officials on 6 February will then begin the process of narrowing the launch window to a specific date. Much will depend on what happens to the shuttle Atlantis.

It is scheduled to fly to the International Space Station on 7 February. If it is held on the ground because of bad weather or further technical problems, the ATV launch date may start to creep to the back of its window.

But when ATV lifts off is probably not so important as when it arrives. It cannot dock when the shuttle is present or in flight - not least because the two vehicles both make use of the US Tracking and Data Relay Satellite System.

"We have built ATV to be almost independent of a lot of the other operations," explained John Ellwood, Esa's ATV mission manager.

                                                         ATV flight animation

Fuelling suits for ATV (Esa/Cnes/Arianespace)
There are about 200 - mostly simple - tasks still to perform
"We have a lot of flexibility in when we actually dock. We will launch as soon as ATV is ready, the launcher is ready and the ground segment is ready.

"We then go to the space station and we have the option of immediately docking if conditions are right or we could loiter. We have a strategy where we go to a point 2,000km in front of the space station and just wait there."

The best times to dock are 15-19 March and 30 March to 5 April. These are periods when the station's alignment to the Sun will give astronauts a clear view of the ATV's approach; cameras will not be blinded by bright light.

Once attached, the ATV - dubbed Jules Verne for its first flight - will stay on-station until August, after which it will be commanded to undock and ditch itself in the Pacific.

Preparation work on the second ATV, likely to fly in 2010, has already begun.

Jonathan.Amos-INTERNET@bbc.co.uk


Posted by:
Lucimary Vargas
Além Paraíba-MG-Brasil
observatorio.monoceros@gmail.com

MESSENGER at Mercury

For the first time in more than 30 years, a spacecraft has returned to Mercury, providing images from sections of the planet that have never been viewed by a spacecraft.
Provided by the Johns Hopkins University
The top left image was taken when MESSENGER was about 21,000 miles from Mercury, and the bottom right image was snapped from a distance of about 250,000 miles. NASA/JHUAPL/Carnegie Institution of Washington [View Larger Image]
Updated January 28, 2008
After MESSENGER completed its successful flyby of Mercury, the Narrow Angle Camera (NAC), part of the Mercury Dual Imaging System (MDIS), took images of the receding planet. Beginning on January 14, 2008, about 100 minutes after MESSENGER's closest pass by the surface of Mercury, until January 15, 2008, about 19 hours later, the NAC acquired one image every four minutes. In all, 288 images were snapped during this sequence; shown here are just 12 of those departing shots.

This large set of departing NAC images has been assembled into a movie, which will be shown today during a NASA press conference at 1 pm EST.
The width of this image is about about 125 miles (200 kilometers), showing that these scarps can be hundreds of miles long on Mercury. NASA/JHUAP/Carnegie Institution of Washington [View Larger Image]
Updated January 27, 2008
As the MESSENGER team continues to study the high-resolution images taken during the Mercury flyby encounter on January 14, 2008, scarps (cliffs) that extend for long distances are discovered. This frame, taken by the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS), shows a region of Mercury's surface previously unseen by spacecraft and a large scarp crossing vertically through the scene, on the far right of the image. This scarp is the northern continuation of the one seen in the NAC image released on January 16.

The presence of many long and high scarps, as discovered from pictures from the Mariner 10 mission in 1974 and 1975, suggests a history for Mercury that is unlike that of any of the other planets in the solar system. These giant scarps are believed to have formed when Mercury's interior cooled and the entire planet shrank slightly as a result. However, Mariner 10 was able to view less than half the planet, so the global extent of these scarps has been unknown. MESSENGER images, like this one, are providing the first high-resolution looks at many areas on Mercury's surface, and science team members are busy mapping these newly discovered scarps to see whether they are common everywhere on the planet.
This image was acquired about 94 minutes after MESSENGER's closest approach to Mercury, when the spacecraft was at a distance of about 20,000 miles (32,000 kilometers). NASA/JHUAP/Carnegie Institution of Washington [View Larger Image]
Updated January 26, 2008
As MESSENGER sped by Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) captured this shot looking toward Mercury's north pole. The surface shown in this image is from the side of Mercury not previously seen by spacecraft. The top right of this image shows the limb of the planet, which transitions into the terminator (the line between the sunlit, day side and the dark, night side) on the top left of the image. Near the terminator, the Sun illuminates surface features at a low angle, casting long shadows and causing height differences of the surface to appear more prominent in this region.

It is interesting to compare MESSENGER's view to the north with the image looking toward the south pole, released on January 21. Comparing these two images, it can be seen that the terrain near the south pole is more heavily cratered while some of the region near the north pole shows less cratered, smooth plains material, consistent with the general observations of the poles made by Mariner 10. MESSENGER acquired over 1200 images of Mercury's surface during its flyby, and the MESSENGER team is busy examining all of those images in detail, to understand the geologic history of the planet as a whole, from pole to pole.
This image of Mercury's surface is about 600 miles (1000 kilometers) across. NASA/JHUAP/Carnegie Institution of Washington [View Larger Image]
Updated January 25, 2008
During MESSENGER's flyby of Mercury on January 14, 2008, part of the planned sequence of observations included taking images of the same portion of Mercury's surface from five different viewing angles. The first view from this sequence was taken just after MESSENGER made its closest approach to Mercury, from a low viewing angle; an image of the first view was released on January 19. The image released here, acquired with the Wide Angle Camera (WAC) on the Mercury Dual Imaging System (MDIS), was snapped 13 minutes after MESSENGER's closest approach with Mercury. The lower two-thirds of this image shows much of the same terrain seen in the first view, but from a much higher viewing angle, as the spacecraft began to pass nearly overhead. At the time of this image, MESSENGER was at a distance of about about 2000 miles (3000 kilometers) from Mercury.

A comparison of the images taken at different viewing angles provides important information about the properties of the materials that make up Mercury's surface. In addition, each view was taken through all 11 of the WAC's narrow-band color filters. The image shown here is from filter 7, which is sensitive to light near the red end of the visible spectrum (750 nm). The MESSENGER team is working to compare these images taken from different perspectives and in different colors to understand surface properties on Mercury. In addition, knowledge of the variation of image properties with viewing angle in this region will permit a more confident comparison of images of other portions of the surface taken at different illumination and viewing angles.
Experience MESSENGER's Mercury flyby virtually
Artist rendition of MESSENGER
Planetary scientists have sent the MESSENGER space probe to Mercury to answer questions left hanging after the visit of the last spacecraft, Mariner 10, in the mid-1970s. NASA / JHUAPL / CIW [View Larger Image]

See Mercury through the "eyes" of MESSENGER's imagers with the Mercury Flyby Visualization Tool. This new web feature offers a unique opportunity to see simulated views of Mercury from MESSENGER's perspective during approach, flyby, and departure, or in real-time (as the observations actually occur).

This tool combines the best available image map of Mercury's surface with observation sequences for the Mercury Dual Imaging System (MDIS), Mercury Atmospheric and Surface Composition Spectrometer (MASCS), and Mercury Laser Altimeter (MLA). The map of Mercury's surface combines Earth-based low-resolution radar images from the Arecibo Observatory in Puerto Rico and image mosaics from the Mariner 10 spacecraft flybys of Mercury in 1974 and 1975.
This image shows just a portion (276 kilometers, or 172 miles, wide) of one frame taken with the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS). In this image alone, 763 craters have been identified and measured (shown in green) along with 189 hills (shown in yellow). Altogether, 491 frames were taken by the NAC to create high-resolution mosaics of Mercury's surface. NASA/JHUAP/Carnegie Institution of Washington [View Larger Image]
Updated January 24, 2008
On January 14, 2008, MESSENGER flew by Mercury and snapped images of a large portion of the surface that had not been previously seen by spacecraft. Ever since the first images were received back on Earth one day later, January 15, MESSENGER team members have been closely examining and studying this "new" terrain with great interest and excitement.

One of many investigations underway includes identifying and measuring the impact craters on these previously unseen regions. The density of craters on the surface of a planet can be used to indicate the relative age of different places on the surface; the more craters the surface has accumulated, the older the surface. By counting craters on different areas of Mercury's surface, a relative geologic history of the planet can be constructed, indicating which surfaces formed first and which formed later. However, this process is also time consuming; Mercury has a lot of craters!

Of course, simply counting the craters is not enough. Each crater has to be measured and classified to fully interpret the differences in crater density. Many small craters form as "secondaries," as clumps of material ejected from a "primary" crater re-impact the surface in the regions surrounding the primary. In order to learn about the history of asteroid and comet impacts on Mercury, scientists have to distinguish between the primary and secondary craters. Once many more craters are measured, MESSENGER researchers will have new insights into the geological history of Mercury.
This color image shows the Matisse crater. NASA/JHUAP/Carnegie Institution of Washington [View Larger Image]
Updated January 23, 2008
As the MESSENGER spacecraft approached Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) snapped this image of the crater Matisse. Named for the French artist Henri Matisse, Matisse crater was imaged during the Mariner 10 mission and is about 130 miles (210 kilometers) in diameter. Matisse crater is in the southern hemisphere and can be seen near the terminator of the planet (the line between the sunlit, day side and the dark, night side) in both the color and single-filter, black-and-white images released previously that show an overview of the entire incoming side of Mercury.

On Mercury, craters are named for people, now deceased, who have made contributions to the humanities, such as artists, musicians, painters, and authors. The International Astronomical Union (IAU) oversees the official process of naming new craters and other new features discovered on bodies throughout the solar system. Scientists studying and mapping unnamed features can suggest names for consideration by the IAU. The 1213 images taken by MESSENGER during its first flyby encounter with Mercury cover a large region of Mercury's surface previously unseen by spacecraft, revealing many new craters and other features that will need to be named.
This visible-infrared image shows an incoming view of Mercury, about 80 minutes before MESSENGER's closest pass of the planet on January 14, 2008, from a distance of about 27,000 kilometers (17,000 miles). NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington [View Larger Image]
Updated January 22, 2008
One week ago, the MESSENGER spacecraft transmitted to Earth the first high-resolution image of Mercury by a spacecraft in over 30 years, since the three Mercury flybys of Mariner 10 in 1974 and 1975. MESSENGER's Wide Angle Camera (WAC), part of the Mercury Dual Imaging System (MDIS), is equipped with 11 narrow-band color filters, in contrast to the two visible-light filters and one ultraviolet filter that were on Mariner 10's vidicon camera. By combining images taken through different filters in the visible and infrared, the MESSENGER data allow Mercury to be seen in a variety of high-resolution color views not previously possible. MESSENGER's eyes can see far beyond the color range of the human eye, and the colors seen in the accompanying image are somewhat different from what a human would see.

The color image was generated by combining three separate images taken through WAC filters sensitive to light in different wavelengths; filters that transmit light with wavelengths of 1000, 700, and 430 nanometers (infrared, far red, and violet, respectively) were placed in the red, green, and blue channels, respectively, to create this image. The human eye is sensitive across only the wavelength range 400 to 700 nanometers. Creating a false-color image in this way accentuates color differences on Mercury's surface that cannot be seen in the single-filter, black-and-white image released last week.

Image sequences acquired through the 11 different MDIS filters are being used to distinguish subtle color variations indicative of different rock types. By analyzing color differences across all 11 filters, the MESSENGER team is investigating the variety of mineral and rock types present on Mercury's surface. Such information will be key to addressing fundamental questions about how Mercury formed and evolved.

Mercury has a diameter of about 3030 miles (4880 kilometers), and the smallest feature visible in this color image is about 6 miles (10 kilometers) in size.
MESSENGER
This image was acquired about 98 minutes after MESSENGER's closest approach to Mercury, when the spacecraft was at a distance of about 21,000 miles (33,000 kilometers). NASA/JHUAPL/CWI [View Larger Image]
Updated January 21, 2008
One week ago, on January 14, 2008, MESSENGER passed 124 miles (200 kilometers) above the surface of Mercury and snapped the first pictures of a side of Mercury not previously seen by a spacecraft. The image to the right shows that previously unseen side, with a view looking toward Mercury's south pole. The southern limb of the planet can be seen in the bottom right of the image. The bottom left of the image shows the transition from the sunlit, day side of Mercury to the dark, night side of the planet, a transition line known as the terminator. In the region near the terminator, the sun shines on the surface at a low angle, causing the rims of craters and other elevated surface features to cast long shadows, accentuating height differences in the image.

This image is just one in a planned sequence of 42 images acquired by the Narrow Angle Camera of the Mercury Dual Imaging System (MDIS). From these 42 images, the MESSENGER team is creating a high-resolution mosaic image of this previously unseen portion of Mercury. During the flyby, MDIS took more than 1,200 images, which are being combined to create multiple mosaics with different resolutions and of different portions of the planet. The creation of high-resolution mosaic images will enable a global view of Mercury's surface and will be used to understand the geologic processes that made Mercury the planet we see today.
This picture provides a global context for the MDIS Narrow Angle Camera (NAC) images taken while MESSENGER was inbound. This image was taken about 80 minutes before closest approach from a distance of about 17,000 miles (27,000 kilometers) and shows features as small as 6 miles (10 kilometers). NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington [View Larger Image]
Updated January 18, 2008
As MESSENGER neared Mercury on January 14, 2008, the spacecraft's Wide Angle Camera on the Mercury Dual Imaging System (MDIS) took images of the planet through each of its 11 filters. This image of the planet's full crescent was taken using the 7th filter, in light near the far-red end of the visible spectrum (750 nm). The image shows portions of Mercury previously seen by Mariner 10, but when Mariner 10 flew by the planet at each of its encounters the Sun was nearly overhead. For this MESSENGER flyby, in contrast, the Sun is shining obliquely on regions near the day/night boundary (called the terminator) on the right-hand side of the crescent, revealing the surface topography in sharp relief. This image illustrates how MESSENGER, during its future flybys and subsequent orbital mission, will teach us much about the portion of Mercury already imaged by Mariner 10, and not just because of its superior camera and close proximity to the planet. The solar lighting geometry makes an enormous difference.

A day after its successful flyby of Mercury, the MESSENGER spacecraft turned toward Earth on Tuesday and began downloading the 500 megabytes of data that had been stored on the solid-state recorder during the encounter. All of those data, including 1,213 images from the Mercury Dual Imaging System (MDIS) cameras, have now been received by the Science Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. Preliminary analysis of these data by the MESSENGER Science Team has confirmed that all seven MESSENGER instruments are healthy and operated as planned during the flyby.

As MESSENGER flew by the planet, it missed its targeted aim point by only 5.12 miles (8.25 kilometers), affording the critical gravity assist needed to continue on a course to become, in 2011, the first spacecraft ever to orbit Mercury. During this first encounter, the payload successfully conducted a carefully orchestrated sequence of observations designed to take full advantage of the geometry of the flyby trajectory and to optimize the science return from each instrument.

In addition to images of the previously unseen portion of the planet's surface, measurements were made that will contribute to the characterization of all aspects of Mercury and its environment, from its metallic core to the far reaches of its magnetosphere. "We have one excited science team," says MESSENGER Project Manager, Peter D. Bedini, of APL, "and their enthusiasm is contagious."

The analysis of these data is just beginning, but there are already indications that new discoveries are at hand.
The image shows a variety of surface textures, including smooth plains at the center of the image, many impact craters (some with central peaks), and rough material that appears to have been ejected from the large crater to the lower right. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington [View Larger Image]
Updated January 17, 2008
As the MESSENGER spacecraft drew closer to Mercury for its historic first flyby, the spacecraft's Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) acquired an image mosaic of the sunlit portion of the planet. This image is one of those mosaic frames and was acquired on January 14, 2008, when the spacecraft was about 11,000 miles (18,000 kilometers) from the surface of Mercury, about 55 minutes before MESSENGER's closest approach to the planet.

This large 120 miles (about 200 milometers) crater was seen in less detail by Mariner 10 more than 3 decades ago and was named Sholem Aleichem for the Yiddish writer. In this MESSENGER image, it can be seen that the plains deposits filling the crater's interior have been deformed by linear ridges. The shadowed area on the right of the image is the day-night boundary, known as the terminator. Altogether, MESSENGER acquired over 1200 images of Mercury, which the science team members are now examining in detail to learn about the history and evolution of the innermost planet.
Mercury
This MESSENGER image was taken from a distance of about 11,000 miles (18,000 kilometers), about 56 minutes before the spacecraft's closest encounter with Mercury. It shows a region roughly 300 miles (500 km) across, and craters as small as 0.6 mile (1 km) can be seen in the image above. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington [View Larger Image]
Updated January 16, 2008
As MESSENGER approached Mercury on January 14, 2008, the spacecraft's Narrow-Angle Camera on the Mercury Dual Imaging System (MDIS) instrument captured this view of the planet's rugged, cratered landscape illuminated obliquely by the Sun. The large, shadow-filled, double ringed crater to the upper right was glimpsed by Mariner 10 more than three decades ago and named Vivaldi, after the Italian composer. Its outer ring has a diameter of about about 125 miles (200 kilometers). MESSENGER's modern camera has revealed detail that was not well seen by Mariner 10, including the broad ancient depression overlapped by the lower-left part of the Vivaldi crater. The MESSENGER science team is in the process of evaluating later images snapped from even closer range showing features on the side of Mercury never seen by Mariner 10. It is already clear that MESSENGER's superior camera will tell us much that could not be resolved even on the side of Mercury viewed by Mariner's vidicon camera in the mid-1970s.
Mercury
The MESSENGER spacecraft snapped this image yesterday morning from a distance of 470,000 miles (760,000 km). The image has a resolution of about 12 miles (20 km) per pixel. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington [View Larger Image]
Updated January 14, 2008
NASA's MESSENGER spacecraft is on track for its first flyby of Mercury today. The craft will explore the planet from as close as 125 miles (200 kilometers).

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) craft, launched August 3, 2004, will be the first spacecraft to study the innermost planet while in orbit around it. Following three flybys during the next 3 years, MESSENGER will reach orbit around Mercury in 2011.

Planetary scientists are eager to get a closer look at the Sun's nearest neighbor.

"We are about to visit Mercury for the first time in more than 30 years, and we can't wait," says MESSENGER principal investigator Sean Solomon of the Carnegie Institution of Washington.

NASA's Mariner 10 is the only other spacecraft to visit the planet closest to the Sun.

"We'll be making close-in observations of the composition of Mercury's surface and atmosphere, and we'll be probing deeper into the planet's magnetosphere than we've ever been," says Solomon.

The MESSENGER probe's Mercury Dual Imaging System cameras began snapping pictures of the planet January 9. NASA plans a mission update on the Mercury flyby January 30.

Visit MESSENGER's online newsroom.
January 8, 2008
On January 9, MESSENGER's Mercury Dual Imaging System cameras began gathering pictures of Mercury as the probe zeros in on the planet.

"With just one week to go before the flyby, the spacecraft is on target to encounter the planet at an altitude of 202 kilometers," says Mission Systems Engineer Eric Finnegan of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. "All subsystems and instruments are operating nominally and configured for the start of the flyby sequence, except for the Mercury Laser Altimeter and part of the Gamma-Ray Spectrometer, which we'll turn on just before the flyby."

Over the next week, the team will make final flyby preparations and upload the final command sequences for the encounter.

"We are about to visit Mercury for the first time in more than 30 years, and we can't wait," says MESSENGER Principal Investigator Sean Solomon of the Carnegie Institution of Washington. "In addition to providing the critical gravity assist that will move MESSENGER along its path toward Mercury orbit insertion in March 2011, this flyby will let us see parts of Mercury never before viewed by spacecraft. We'll be making close-in observations of the composition of Mercury's surface and atmosphere, and we'll be probing deeper into the planet's magnetosphere than we've ever been. We expect many surprises."

On December 19th, MESSENGER's 19th trajectory correction maneuver (TCM-19) changed the spacecraft's velocity by 3.6 feet per second (1.1 meters per second), directing MESSENGER closer to its intended target for the first flyby. TCM-19 went so well that the mission design and navigation teams have decided that a TCM scheduled for January 10 will not be needed.

"Cancellation of this maneuver is a demonstration of the near-perfect execution of TCM-19 just prior to the start of the holiday season," says Finnegan.
 
Posted by:
Lucimary Vargas
Além Paraíba-MG-Brasil
observatorio.monoceros@gmail.com

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