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The Hubble Space Telescope has photographed galaxies whose light set out more than 13 billion years ago. One of them, GN-z11, found in 2015, appears as it was only about 400 million years after the Big Bang, so astronomers can see the universe when it was young.

NASA, 1990

ScienceTechnology

The story behind the card

Light travels at a fixed speed, so looking far into space also means looking back in time. Hubble, a joint project of NASA and the European Space Agency, was launched on 24 April 1990; once a flaw in its main mirror was corrected in 1993, it began sending back sharp images of the distant universe. In December 1995 it stared at one tiny patch of sky for ten days, and the resulting Hubble Deep Field showed about 3,000 galaxies. GN-z11, reported in 2016 by a team led by Pascal Oesch, remained the most distant galaxy known until the James Webb Space Telescope found even earlier ones in 2022. The universe itself is about 13.8 billion years old.

Türkçe oku
Hubble Uzay Teleskobu, ışığı yola çıkalı 13 milyar yıldan fazla olan galaksileri görüntüledi. Bunlardan biri 2015'te bulunan GN-z11'dir: Onu, Büyük Patlama'dan yalnızca 400 milyon yıl kadar sonraki hâliyle görürüz. Gökbilimciler böylece evrenin gençlik çağına bakabiliyor.

Işık sabit bir hızla yol aldığı için uzayın derinliklerine bakmak, aynı zamanda geçmişe bakmak demektir. NASA ile Avrupa Uzay Ajansı'nın ortak projesi olan Hubble, 24 Nisan 1990'da fırlatıldı. Ana aynasındaki kusur 1993'te giderildikten sonra uzak evrenin net görüntülerini göndermeye başladı. Aralık 1995'te gökyüzünün küçücük bir parçasına on gün boyunca baktı; ortaya çıkan Hubble Derin Alan görüntüsünde yaklaşık 3.000 galaksi vardı. Pascal Oesch'in yönettiği ekibin 2016'da duyurduğu GN-z11, James Webb Uzay Teleskobu 2022'de daha eski galaksiler bulana kadar bilinen en uzak galaksiydi. Evrenin yaşı ise yaklaşık 13,8 milyar yıldır.

Sources and further reading

Background reading: Hubble Space Telescope
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