When we look at telescopes, we only associate them with seeing objects from a distance. However, as telescopes work by collecting light through the diameter of the lens or mirror used, it can also be used to see further back in time. In this post we describe the earliest time in the universe we can observe.
Telescopes look back in time because it takes time for light to travel across space. As fast light travels, it can take extraordinary amounts of time to traverse intergalactic distances. If you look at distant galaxies, you are seeing them as they were millions or billions of years ago.
Of course, you can’t do this with any old telescope to see very distant galaxies. You need a specialized instrument to see the earliest time in the universe. So, don’t try to look for them yourself.
It’s only with the help of telescopes such as the Hubble Space Telescope, James Webb Telescope, and the currently in construction Giant Magellan Telescope. But how far back can we see? Well, it’s up to us to find out.
The Earliest Time In The Universe We Can Observe
Many astronomers have wanted to see the creation of the universe, and many dream of the day that we can see the Big Bang. However, we can’t go back to 13.8 billion years ago because of how the Universe has developed. It’s quite likely that the earliest element of the Universe that we will ever view is the cosmic microwave background radiation.
It’s unlikely that we’ll ever be able to see the Big Bang, as we’ll explain further below. So far, the furthest we can see is a few hundred thousand years after the Big Bang.
Many people assume that we’ve only seen as far as we can with the James Webb Space Telescope. This intrument has observed distant galaxies as they appeared 13.5 billion years ago. This means we can go as far back as a few hundred thousand years after the Big Bang occurred.
Using infrared-sensing instruments, the James Webb Space Telescope can see ancient galaxies. Some of the stars the James Webb Telescope sees may be long dead, but it’s fascinating to see just how far back we can go. We must observe very distant galaxies in infrared as the light has been redshifted to these wavelengths.
The James Webb Space Telescope may be the most recent to look back. However, other telescopes have seen farther. The two biggest telescopes to go into orbit to examine the Big Bang were the Wilkinson Microwave Anisotropy Probe and Planck.
In fact, using Planck, we could define the universe’s age.
What Do Scientists Think The Big Bang Looked Like?
We can’t go back to the Big Bang. However, many scientists have already explained what the Big Bang looked like. Some 13.8 billion years ago, everything in the universe was created as a small energy point.
Many assume the universe is dark and cold and must have always been that way. However, that wasn’t always the case.
At the time of the Big Bang, the universe was only a collection of particles. Truthfully, if you even looked back in time to a second after the Big Bang, you wouldn’t be able to see anything. At this point, light didn’t exist.
Everything was opaque; once there was light, it was too bright to be seen with our naked eyes. If we did see it, we would have experienced great damage.
The earliest we could see is just 380,000 years after the universe began to expand. That’s because before that time light could not travel unhindered. It traveled a short distance before being absorbed by an atom. At 380,000 years after the Big Bang, the Universe cooled enough for light to travel freely. It is this event that is recorded in the cosmic microwave background radiation.
What Telescopes Have Gone Back Farthest?
When looking back in time, we’ve had several telescopes that have traveled the farthest. As we mentioned before, the James Webb Telescope, the successor to the Hubble Telescope, could record the light of an object known to exist within the first billion years after the Big Bang.
Initially, the Hubble Telescope broke the record by finding a roughly four billion-year-old star.
To put this star into perspective, the light found by the James Webb telescope took 12.9 billion years to reach the Earth. Most galaxies appear as small smudges from this type of distance as the light from millions of stars blends.
However, a gravitational lens magnified and distorted the galaxy, so it appeared in a Sunrise Arc. Gravitation lenses allow us to see further back in time than what we would otherwise be able to achieve.
The telescope which has allowed us to map the foundation of the universe and help us understand the Big Bang was the Wilkinson Microwave Anisotropy Probe or WMAP for short.
Using WMAP, scientists could figure out the universe’s age and appearance. It even found the percentage of dark matter in the universe and made leaps in cosmology.
After WMAP was switched off, it was succeeded by Planck. Planck was a more advanced spacecraft that could gain a better idea of the universe’s age. It did this by collecting higher-resolution data.
What is the Most Distant Object Observed
Not surprisingly, the most distant object so far found (as of October 2024) was from JWST. JADES-GS-z14-0 is located at a stunning distance of 33.6 billion light-years from Earth. It is a galaxy that existed just 290 million years after the Big Bang (Wikipedia). The galaxy is 1600 light-years wide and is very luminous.
You may know that the Universe is only 13.8 billion years old and ask how something can be more than 13.8 billion light-years away. It would be a good question. It is now located so far away because the Universe has expanded in that time. In essence, the space between us and the galaxy has become a lot bigger.
Are There Plans To See Further Back?
Scientists haven’t given up on understanding the universe’s age and what is out there. Currently, they are working on the Giant Magellan Telescope, which they hope will allow them to look back to see the birth of stars, galaxies, and events that occurred soon after the Big Bang.
Unlike the Hubble and James Webb Telescopes, the Giant Magellan Telescope will remain on Earth as a ground-based telescope. While it won’t detect the same infrared frequencies that telescopes in space have, it will have a revolving power that is four times that of the James Webb Telescope.
Final Thoughts
While it’s impossible to see the Big Bang as it happened, scientists constantly look for new ways to understand the universe’s history.
Currently, we see up to several thousand years after the Big Bang 13.8 million years ago. Since then, scientists have tried to understand dark matter and other galaxies that have existed in the past.
As it is, the Big Bang itself is incomprehensible to the human eye, so we can only learn about it by examining objects as far back into the past as we can see (Also check out Why Can’t We See Past The Cosmological Horizon?).
If you’d like to know more, please check out some of our other helpful articles about astronomy.
Hi, my name is Jason Anderson, and I am a Physics Professor. Ever since I was a kid, I’ve been fascinated with space, the universe, the moon, you name it. I spent hours and hours at the planetarium close to my hometown, wondering what else could be out in the universe.
Since then, I’ve been an avid stargazer and astronomer, and love nothing more than spending my time charting stars, observing planets, and finding constellations.
This is why I decided to start Telescope Guru. I only wish to share this fun pastime with the world. With this site, I hope to answer all of your questions relating to astronomy, telescopes, and stargazing.
