Table of Contents
- 1 How do we see galaxies light years away?
- 2 How can we see galaxies so far away?
- 3 How many light-years away can we observe?
- 4 How are galaxies photographed?
- 5 How do scientists observe and study the universe?
- 6 How do they know how many light-years away a planet or galaxy is?
- 7 How did astronomers spot this galaxy from space?
- 8 How long has light been traveling through the universe?
How do we see galaxies light years away?
The telescope can see and focus this vast distance by leveraging the power of gravity. Gravity distorts space in such a way that it makes an “optic” that channels light towards Hubble and gives it the ability to see galaxies that are normally too far away to be studied with current technology and physical telescopes.
How can we see galaxies so far away?
So astronomers measure a galaxy’s redshift from its spectrum, use the Hubble constant plus a model of the universe to turn the redshift into a distance, and use the distance and the constant speed of light to infer how far back in time they are seeing the galaxy—the look-back time.
How do scientists see galaxies?
The most distant galaxies are caught up in the expansion of the Universe, causing distant galaxies to redshift past the point where our optical and near-infrared telescopes (like Hubble) could detect them. Finite sizes and observing times meant that only the galaxies above a certain brightness threshold could be seen.
How do scientists know how many light years away?
There is no direct method currently available to measure the distance to stars farther than 400 light years from Earth, so astronomers instead use brightness measurements. Astronomers can therefore look at a distant star and determine its color spectrum. From the color, they can determine the star’s actual brightness.
How many light-years away can we observe?
In a non-expanding Universe, as we covered earlier, the maximum distance we can observe is twice the age of the Universe in light years: 27.6 billion light years. But in the Universe we have today, we’ve already observed galaxies more distant than that!
How are galaxies photographed?
The wide-field camera takes large images of the universe. When solar radiation interferes with ultraviolet light, scientists use the solar blind camera, which captures hot stars and other ultraviolet-emitting bodies. The high-resolution camera could take pictures inside galaxies.
How can NASA see other galaxies?
The telescope has helped scientists understand how planets and galaxies form. Galaxies contain billions of stars. A picture called “Hubble Ultra Deep Field” shows some of the farthest galaxies ever seen. Pictures from Hubble help scientists learn more about the whole universe.
How do scientists know so much about space?
Things in space which release or reflect light, like stars or planets, can be seen either with the naked eye or with telescopes. By looking at that light, scientists can either directly tell where objects in space are, or at least can make deductions about their locations.
How do scientists observe and study the universe?
Here are some of the ways: (1) We use computers to help run big telescopes, the instruments that collect data, and the satellites that study stars and planets. (2) We use computers to analyze the data and try to understand what the data mean.
How do they know how many light-years away a planet or galaxy is?
Astronomers can use what are called surface brightness fluctuations (SBF, for short), along with the color of a galaxy, to calculate how far away it is from earth. Most galaxies measured in this way are millions of light years away.
How far can we observe galaxies in the universe?
In a non-expanding Universe, as we covered earlier, the maximum distance we can observe is twice the age of the Universe in light years: 27.6 billion light years. But in the Universe we have today, we’ve already observed galaxies more distant than that!
What is the farthest galaxy yet detected?
Update 02/03/16: Here are the newest candidates (as of September and May 2015 respectively) for farthest galaxy yet detected. EGS8p7 at more than 13.2 billion light years away, and EGS-zs8-1 at 13.1 billion light years away.
How did astronomers spot this galaxy from space?
To spot this galaxy, astronomers used the powerful gravity from the massive galaxy cluster MACS J0647+7015 to magnify the light from the distant galaxy; this effect is called gravitational lensing.
How long has light been traveling through the universe?
Imagine the Universe! Current observations suggest that the Universe is about 13.7 billion years old. We know that light takes time to travel, so that if we observe an object that is 13 billion light years away, then that light has been traveling towards us for 13 billion years.