Although the Hubble Space Telescope has given us an unprecedented look at galaxies far beyond our own, there are still some that it just can't see.
Enter MUSE, an instrument on the European Southern Observatory's (ESO) Very Large Telescope (VLT) which recently looked at a patch of sky once studied by Hubble, unveiling more galaxies than ever before.
However, what's most amazing about the observations made by MUSE is that it did this in just 27 hours, where Hubble's original survey took several days.
In 1995, Hubble observed the skies for a project called the Hubble Deep Field. These observations taught us a lot about the objects in our Universe when it was still young. Two years later, Hubble did another similar mission and looked at the southern sky, the Hubble Deep Field South.
At the time, these observations were unprecedented. However, they left many unanswered questions and scientists wanted to know more about these new galaxies discovered. How far away were these galaxies? What were they made of?
Unfortunately, the only way to answer these questions at the time was by looking at these patches of sky with many other instruments and telescopes, which often proved time-consuming and difficult.
MUSE, however, changes all that. It can not only observe more galaxies than ever before, but it can also unveil the properties of these galaxies. It can also do so quickly.
One of MUSE's first missions was looking at the Hubble Deep Field South. After MUSE studied that part of the sky, scientists found the results astonishing. Although MUSE spent less time than Hubble making its observations, it found more than 20 objects that Hubble never saw.
"After just a few hours of observations at the telescope, we had a quick look at the data and found many galaxies - it was very encouraging," says Roland Bacon, the principal investigator of MUSE. "And when we got back to Europe we started exploring the data in more detail."
MUSE's observations aren't just images and pixels. It also studies the galaxies with spectral light, which gives scientists details on everything from the distance of a galaxy to its composition. After studying the Hubble Deep Field South, scientists measured distances to nearly 190 galaxies, including some that existed during the Universe's early years.
Scientists also hope that MUSE can help them further study the closer galaxies and tell us more about their different features, as well as how they rotate. This gives us a new picture of what galaxies like ours were like when they were younger, as well as how they evolved.
"We will be able to study thousands of galaxies and to discover new extremely faint and distant galaxies," says Bacon. "These small infant galaxies, seen as they were more than 10 billion years in the past, gradually grew up to become galaxies like the Milky Way that we see today."
