The upcoming launch of James Webb Space Telescope It presents unprecedented new opportunities for astronomers. It is also a good opportunity to reflect on what previous generations of telescopes have shown us.
Astronomers rarely use their telescopes to take pictures. Images in astrophysics are usually created through a process of scientific inference and imagination, sometimes visualized in the artist’s impressions of what the data suggests.
Choosing just a few photos wasn’t easy. My selection was limited to images produced by publicly funded telescopes that reveal some interesting science. I tried to avoid images that are too popular and are already widely viewed.
The selection below is subjective and I’m sure many readers can advocate different options. Feel free to share it in the comments.
1. Buyer poles
The first photo you selected was produced by NASA Juno’s missionwhich is currently in orbit Jupiter. Photo was taken in october 2017 When the spacecraft was 18,906 kilometers from the tops of Jupiter’s clouds. It captures a cloud system in the planet’s northern hemisphere and represents our first view of Jupiter’s (North Pole) poles.
This image is based on the detection of complex flow patterns, similar to hurricanes in the Earth’s atmosphere, and surprising effects caused by a variety of clouds at different altitudes, sometimes casting shadows on the layers of clouds below.
I chose this image for its beauty as well as the surprise it caused: the parts of the planet near its north pole look very different from the parts we saw earlier near the equator. By looking down at Jupiter’s poles, Juno showed us a different view of a familiar planet.
2. The Eagle Nebula
Astronomers can obtain unique information by building telescopes that are sensitive to «colour» light that our eyes can see. The familiar rainbow of colors is only a tiny fraction of what physicists call the electromagnetic spectrum.
Beyond red is infrared rays, which carry less energy than optical light. The infrared camera can see things that are too cold to be detected by the human eye. In space, it can also see through dust, which otherwise completely blocks our view.
The James Webb Space Telescope will be the largest infrared observatory ever launched. So far, ESA Herschel Space Observatory was the biggest. The next image I’ve chosen is Herschel’s view of star formation in the Eagle Nebula, also known as M16.
A nebula is a cloud of gases in space. The Eagle Nebula is 6,500 light-years from Earth, which is very close by astronomical standards. This nebula is a site of strong star formation.
Close-up view of an element near the center of this image is called «Pillars of CreationAppearing a little like the thumb and forefinger pointing up and a little to the left, these plumes protrude into a cavity in a giant cloud of molecular gas and dust. It is swept by winds from recently emerged energetic new stars forming deeper within the cloud.
3. Galactic Center
The bright white region at the bottom right of the image is the center of our galaxy. contains a file Black hole Call Sagittarius A*, a group of stars and the remains of a massive star that exploded as a supernova about 10,000 years ago.
else star groups also visible. The Quintuplet in the lower left of the image is inside a bubble where star winds have removed local gas and dust. At the top left is a group called arcs, named for the luminous gas arcs that extend above and beyond the image. These two groups include some of the most massive stars known.
4 — Abel 370
On scales much larger than individual galaxies, the universe is made up of a network of filaments (long, connected filaments) of dark matter. Some of the most dramatic visible objects are clusters of galaxies that form at the intersection of filaments.
If we look at clusters of nearby galaxies (relatively speaking, of course), we can see exciting evidence that Einstein was right when he asserted that the mass of space curves. One of the most beautiful examples of this distortion of space can be seen in the Hubble image Ebel 370, released in 2017.
Abell 370 is a group of hundreds of galaxies about 5 billion light-years away. In the photo you can see long arcs of light. These are enlarged and distorted images of galaxies much further away.
The mass of the mass distorts spacetime and bends light from distant objects, inflating them and in some cases creating multiple images of the same distant galaxy. This phenomenon is called a gravitational lens because the twisted spacetime acts like an optical lens.
The highlight of these enlarged images is the thick bright arc above and to the left of the center of the image. This arc is called the «dragon», and it consists of two images of the same distant galaxy at its head and tail. Overlapping images of many distant galaxies form an arc of the Dragon’s body.
These gravitationally magnified images are useful to astronomers because magnification reveals more details about a distant lensed object than can be seen. In this case, the star cluster in the lenticular galaxy can be examined in detail.
5. Hubble’s ultra-deep field
In an inspiring idea, astronomers decided to direct Hubble to an empty patch of sky for several days to discover objects so far away that it can be seen at the edge of the visible universe.
the Hubble’s ultra-deep field It contains approximately 10,000 objects, almost all of which are very distant galaxies. The light from some of these galaxies has been traveling for more than 13 billion years, when the universe was only about half a billion years old.
Some of these objects are among the oldest and farthest known. Here we see the light from the ancient stars whose local contemporaries have long since disappeared.
The oldest galaxies formed during the era of reionization, when the weak gas in the universe was first immersed in starlight that was able to separate electrons from hydrogen. This was the last major change in the properties of the universe as a whole.
The fact that light carries so much information, allowing us to piece together the history of the universe, is remarkable. The launch of the James Webb Space Telescope will give us some greatly improved infrared images, and will inevitably raise new questions to challenge future generations of scientists.