15 Things We’ve Learned About the Universe From the Hubble Space Telescope

Launched nearly 30 years ago, the Hubble Space Telescope is a veritable manufacturing plant of discoveries, solving mysteries of the universe and raising tantalizing new possibilities about where we’ve come from and where we are going. Here are 15 things we’ve learned from the Hubble Space Telescope.

1. The universe is 14 billion years old.  

Galaxies are moving apart, which means at some point they must have been close together. One method to figure out the age of the universe involved using the Hubble Space Telescope to determine speed, distance, and acceleration. Scientists could then work out the time necessary for current galactic distances to be reached. Now we know that the universe's birthday cake requires 14 billion candles.

2. Quasars reside in the cores of galaxies.

Quasars are extraordinarily weird. They're the size of our solar system but as bright as entire galaxies that are populated with billions and billions of stars. Scientists used the Hubble Space Telescope to track down the home of these celestial high beams and found them in galactic cores.

3. We can see the universe's baby photos. 

There's no "now" in space. Space is big, and light takes a very long time to reach our little corner of the universe. When the Hubble Space Telescope peered deeply into space to photograph distant galaxies, scientists were astonished by the number it captured: 3000. But none of the 3000 galaxies pictured in the "Hubble Deep Field" were recent. Hubble had photographed galaxies from billions of years in the past—that's how long it took the light to reach us. In other words, the Hubble Deep Field is comprised of galactic baby pictures from the dawn of time. 

4. We thought the expansion of the universe was slowing down. We were wrong. 

It just makes sense that after the literal eternity which has elapsed since the Big Bang, the expansion of the universe would slow. The Hubble Space Telescope has news for us, though: The expansion of the universe is actually increasing in speed. Why? Dark energy. While we're not even sure what dark energy is, the working theory is that it's responsible for the acceleration.  

5. PLUTO HAS MORE MOONS THAN WE ANTICIPATED. 

In 2005, scientists discovered two new moons of Pluto using the Hubble Space Telescope. After the New Horizons spacecraft to Pluto launched in January 2006, the possibility of undiscovered moons became a big worry. Unlike planets, small moons can lack the gravity to hold on to their collision debris. A rock hitting a tiny moon might send many more rocks back into space. Because debris the size of a grain of rice could have destroyed New Horizons, the team went to work discovering as many moons as it could. In the end, Hubble discovered four moons around Pluto, bringing its total number to five. New Horizons scientists modeled the newly discovered moons, and were able to avoid disaster.                                                          

6. We've seen the same moment of time on more than one occasion.

To those of us without advanced degrees in the subject, physics can seem really weird. There might be nothing weirder, then, than the Groundhog Day supernova. Nine billion years ago, a star blew up. Gravity from intermediary galaxies have bent and influenced light rays from this doomed star in such a way that the light takes different paths to arrive here, some longer than others. This means we've seen the exact same moment in time more than once. So far, scientists have observed the same supernova four times and counting

7. Supermassive black holes are real.

Wikimedia Commons // CC BY-SA 2.5

Einstein predicted black holes with his general theory of relativity, though actually finding them has been something of a problem for scientists. In 1971, Cygnus X-1 was all but confirmed as a black hole, ending years of debate. But around the same time, a new hypothesis was emerging about supermassive black holes that resided at the centers of galaxies. Enter the Hubble Space Telescope, which found in galaxy M87 "conclusive evidence" of the existence of supermassive black holes. It is one of the most astonishing discoveries in the telescope's three decades. In 2019, an international team of scientists took the first-ever photo of a black hole, and it was the supermassive one at the center of the M87 galaxy.

8. We know the colors of exoplanets. 

Exoplanets are planets that orbit distant stars. Many have been discovered, and the Hubble Space Telescope has been instrumental in fleshing out what we know about these mysterious worlds. Hubble instruments have performed atmospheric studies of such planets similar to GJ 1132b, a Venus-like world 230 trillion miles away that was discovered in 2015. Hubble has also helped scientists figure out the actual color of an exoplanet—a first. The creatively named HD 189733b is now known to be cobalt blue. (Its color comes not from oceans but from its silicate atmosphere.) Hubble didn't stop there, though. It has also helped scientists create the first exoplanet weather map. The forecast for WASP-43b: hot—3000°F—with occasional temperatures reaching a “cool” 1000°F.

9. Jupiter's moon Ganymede has an ocean.

Ganymede made quite a splash earlier this year when a subsurface ocean was discovered. But how was that determined, anyway? Scientists used the Hubble Space Telescope to watch auroras on Ganymede. When the auroras didn't behave as expected, scientists knew they had something special. In a statement reported by Space.com, geophysicist Joachim Saur said:

"I was always brainstorming how we could use a telescope in other ways. … Is there a way you could use a telescope to look inside a planetary body? Then I thought, the aurorae! Because aurorae are controlled by the magnetic field, if you observe the aurorae in an appropriate way, you learn something about the magnetic field. If you know the magnetic field, then you know something about the moon's interior."

In this case, that interior was an ocean. 

10. Europa has plumes, and that might indicate signs of life. 

When a world has a subsurface ocean, the great challenge is trying to figure out how to drill down into it and take samples. Plumes make the job much easier. In essence, plumes are giant geysers firing the ocean into space. So instead of spacecraft somehow going into the ocean, plumes help the ocean come to the spacecraft. This is especially important for a world like Europa, which is thought by many to harbor life. In 2013, Hubble scientists discovered plumes on Europa, one of Jupiter's moons. Now that NASA has built a flagship mission around Europa, scientists might soon have a chance at sampling it for life. 

11. There are new worlds that we can actually visit. 

The first phase of New Horizons has been successful beyond the dreams of even Alan Stern, the mission's leader. Moreover, the spacecraft still has a lot of power. It is presently flying through the mysterious Kuiper Belt—a ring composed primarily of frozen volatiles beyond Neptune—where there is much to learn. The New Horizons team has used Hubble to find new targets for a spacecraft study: in January 2019, the spacecraft beamed back images of a Kuiper Belt object (KBO) dubbed Ultima Thule in the farthest fly-by of a KBO ever achieved. The snowman-shaped object is 4 billion miles from the Sun.

12. There was a 10th planet in our solar system. 

Hubble is good for more than studying exoplanets, moons, and baby galaxies. Scientists have used the space telescope to study strange new planets in our own solar system. Before the International Astronomical Union meddled with the definition of "planet," a 10th planet in the solar system—Eris—was discovered. The secrets of Eris, a Kuiper Belt Object that is now categorized as the second-largest dwarf planet (behind Pluto, which was demoted to dwarf planet status in 2006), were unlocked by Hubble, including its size and mass.                            

13. Dark matter can appear in clumps.

Thanks to Hubble, scientists have been able to map dark matter in the universe, and have worked out that normal matter (things made of atoms—in this case, galaxies) gathers near dense areas of dark matter. In addition, Hubble's findings suggest that dark matter clumps together as it collapses under gravity. NASA compares Hubble's success in mapping dark matter to "mapping a city from nighttime aerial snapshots showing only streetlights. … These new map images are equivalent to seeing a city, its suburbs and country roads in daylight for the first time." 

14. It's a galaxy-eat-galaxy universe out there.

When scientists used Hubble to study the Andromeda galaxy, they expected to find very old stars. They were surprised, then, to learn that the stars ranged in age from 6 to 13 billion years old. They suspect that the young stars found their way into Andromeda through cosmic collisions. In other words, Andromeda ate smaller galaxies and kept the stars for itself. 

15. PROTOPLANETARY DISKS ARE OBSERVABLE.

For a long time, scientists believed that "protoplanetary disks"—disks of dust around stars that might form solar systems—would be impossible to see. It was thought that the disks would be obscured by clouds of gas. Hubble proved that suspicion wrong, and has discovered many such disks. As a result, scientists have new insights into how planets and their associated solar systems are created. 

Take Advantage of Amazon's Early Black Friday Deals on Tech, Kitchen Appliances, and More

Amazon
Amazon

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Even though Black Friday is still a few days away, Amazon is offering early deals on kitchen appliances, tech, video games, and plenty more. We will keep updating this page as sales come in, but for now, here are the best Amazon Black Friday sales to check out.

Kitchen

Instant Pot/Amazon

- Instant Pot Duo Plus 9-in-115 Quart Electric Pressure Cooker; $90 (save $40) 

- Le Creuset Enameled Cast Iron Signature Sauteuse 3.5 Quarts; $180 (save $120)

- KitchenAid KSMSFTA Sifter with Scale Attachment; $95 (save $75) 

- Keurig K-Mini Coffee Maker; $60 (save $20)

- Cuisinart Bread Maker; $88 (save $97)

- Anova Culinary Sous Vide Precision Cooker; $139 (save $60)

- Aicook Juicer Machine; $35 (save $15)

- JoyJolt Double Wall Insulated Espresso Mugs - Set of Two; $14 (save $10) 

- Longzon Silicone Stretch Lids - Set of 14; $13 (save $14)

HadinEEon Milk Frother; $37 (save $33)

Home Appliances

Roomba/Amazon

- iRobot Roomba 675 Robot Vacuum with Wi-Fi Connectivity; $179 (save $101)

- Fairywill Electric Toothbrush with Four Brush Heads; $19 (save $9)

- ASAKUKI 500ml Premium Essential Oil Diffuser; $22 (save $4)

- Facebook Portal Smart Video Calling 10 inch Touch Screen Display with Alexa; $129 (save $50)

- Bissell air320 Smart Air Purifier with HEPA and Carbon Filters; $280 (save $50)

Oscillating Quiet Cooling Fan Tower; $59 (save $31) 

TaoTronics PTC 1500W Fast Quiet Heating Ceramic Tower; $55 (save $10)

Vitamix 068051 FoodCycler 2 Liter Capacity; $300 (save $100)

AmazonBasics 8-Sheet Home Office Shredder; $33 (save $7)

Ring Video Doorbell; $70 (save $30) 

Video games

Sony

- Marvel's Spider-Man: Game of The Year Edition for PlayStation 4; $20 (save $20)

- Marvel's Avengers; $27 (save $33)

- Minecraft Dungeons Hero Edition for Nintendo Switch; $20 (save $10)

- The Last of Us Part II for PlayStation 4; $30 (save $30)

- LEGO Harry Potter: Collection; $15 (save $15)

- Ghost of Tsushima; $40 (save $20)

BioShock: The Collection; $20 (save $30)

The Sims 4; $20 (save $20)

God of War for PlayStation 4; $10 (save $10)

Days Gone for PlayStation 4; $20 (save $6)

Luigi's Mansion 3 for Nintendo Switch; $40 (save $20)

Computers and tablets

Microsoft/Amazon

- Apple MacBook Air 13 inches with 256 GB; $899 (save $100)

- New Apple MacBook Pro 16 inches with 512 GB; $2149 (save $250) 

- Samsung Chromebook 4 Chrome OS 11.6 inches with 32 GB; $210 (save $20) 

- Microsoft Surface Laptop 3 with 13.5 inch Touch-Screen; $1200 (save $400)

- Lenovo ThinkPad T490 Laptop; $889 (save $111)

- Amazon Fire HD 10 Tablet (64GB); $120 (save $70)

- Amazon Fire HD 10 Kids Edition Tablet (32 GB); $130 (save $70)

- Samsung Galaxy Tab A 8 inches with 32 GB; $100 (save $50)

Apple iPad Mini (64 GB); $379 (save $20)

- Apple iMac 27 inches with 256 GB; $1649 (save $150)

- Vankyo MatrixPad S2 Tablet; $120 (save $10)

Tech, gadgets, and TVs

Apple/Amazon

- Apple Watch Series 3 with GPS; $179 (save $20) 

- SAMSUNG 75-inch Class Crystal 4K Smart TV; $998 (save $200)

- Apple AirPods Pro; $169 (save $50)

- Nixplay 2K Smart Digital Picture Frame 9.7 Inch Silver; $238 (save $92)

- All-New Amazon Echo Dot with Clock and Alexa (4th Gen); $39 (save $21)

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Canon EOS M50 Mirrorless Camera with EF-M 15-45mm Lens; $549 (save $100)

DR. J Professional HI-04 Mini Projector; $93 (save $37)

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Don't Miss Saturn And Jupiter's Great Conjunction on the Winter Solstice

Paul Williams, Flickr // CC BY-ND 2.0
Paul Williams, Flickr // CC BY-ND 2.0

In 2020, skygazers were treated to meteor showers, a new comet, and a Halloween blue moon. One of the last major astronomical events of the year is set to fall on the night of the winter solstice. On December 21, look up to catch Saturn in conjunction with Jupiter.

What is the conjunction of Saturn and Jupiter?

In astronomy, a conjunction occurs when two planets appear exceptionally close in the night sky. Two of our solar system's gas giants will share a celestial "kiss" on the longest night of the year. The rare meeting of Saturn and Jupiter is known as the "great conjunction" by astronomers.

Though conjunctions between the planets are fairly common, Saturn and Jupiter only get together once in a generation. Their last conjunction happened 20 years ago in the year 2000. Even if you were around for the last one, 2020's planetary meet-up is worth catching. Saturn and Jupiter will come within 0.1° of each other, or about one-fifth the width of a full moon. The last time the two planets came that close was in 1653, and they won't match that proximity again until 2080.

How to see the conjunction of Saturn and Jupiter

Saturn and Jupiter have been inching closer throughout October and November. You can find them now by looking for Jupiter, currently the brightest planet in the night sky, right after sunset. Saturn will appear just east of Jupiter as a dimmer planet with a golden hue.

As autumn wanes, the two planets will gradually bridge the space between them until they reach conjunction on winter solstice. On Monday, December 21, the planets will be so close that they may form a coalescence. That happens when the light from two planets appear to shine as a single star. When that happens, the super-bright body will be easy to spot.