NASA finds that there are far fewer galaxies than previously thought, with figures in the billions instead of trillions
- Previous estimates suggest that there were about two trillion galaxies
- But new data from NASA’s New Horizons spacecraft suggests that’s not the case
- Instead, NASA now estimates that there are hundreds of billions of galaxies
NASA has revealed that there are far fewer galaxies in the universe than previously thought.
New measurements taken by NASA’s New Horizon spacecraft put the figures at hundreds of billions, rather than the two trillion previously reported.
The findings indicate that the universe may be much less crowded than the previous estimates suggested.
The Milky Way may be one of the only billions of galaxies in the universe, instead of billions according to the previous estimate
In the study, NASA made new measurements of the faint background glow of invisible galaxies.
Mark Postman, of the Baltimore Space Telescope Institute of Science and lead author of the study, said, “It’s an important number to know: how many galaxies are there?” We just don’t see the light of two trillion galaxies.
Previous estimates were based on deep sky observations from NASA’s Hubble Space Telescope.
However, Hubble relied on mathematical models to estimate the number of galaxies, as it was believed that many galaxies were beyond the ability of the space telescope to detect visible light.
Unfortunately, Hubble still suffers from light pollution due to its position in the inner solar system.
To overcome this problem, NASA turned to its New Horizons spacecraft, which experiences an ambient sky 10 times darker than the darkest sky seen by Hubble.
Tod Lauer of NSF’s NOIRLab, lead author of the study, said: “Such measures are extremely difficult. A lot of people have been trying to do this for a long time.
“New Horizons provided us with a point of view for measuring cosmic optical background better than anyone has been able to do.”
NASA addressed its New Horizons spacecraft, which experiences an ambient sky 10 timers darker than the darkest sky seen by Hubble
To estimate how many galaxies there really are, the team analyzed existing images from New Horizons.
To cause the faint background glow in some images, NASA was forced to remove the light from the stars in the Milky Way that was reflected on the camera.
Fortunately, the remaining signal was almost measurable, allowing for a more accurate estimate of the number of galaxies.
Now NASA is planning a follow-up study with its upcoming James Webb space telescope.
NASA said: ‘NASA’s upcoming James Webb space telescope may help solve the mystery. If they are weak, individual galaxies are the cause, Webb’s ultra-deep field observations should be able to detect them.
This study is accepted for publication in the Astrophysical Journal.
WHAT IS A MONSTER GALAXY?
Monster galaxies, also known as starburst galaxies, are believed to be ancestors of massive galaxies such as the Milky Way in today’s universe.
Ancient objects appeared shortly after the Big Bang and are characterized by rapid star formation and massive growth, which gave birth to new stars at rates thousands of times faster than in our own galaxy.
This leads to small but incredibly dense galaxies, which quickly burn all of their cosmic gas, the “fuel” used to create new stars.
Once they consume this gas, some about 100 million years after birth, they become dormant or “red and dead” galaxies, common in our current universe.
Scientists hope that the study of mysterious objects will provide answers to key questions about the formation and evolution of modern galaxies, such as the Milky Way.
Monster galaxies, also known as starburst galaxies, are believed to be ancestors of massive galaxies such as the Milky Way in today’s universe. This image is an artist’s impression of ZF-COSMOS-20115, a monster galaxy discovered in 2017