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7 Facts That Will Make You Feel Very Small

Earth, our home planet, is the fifth largest planet in our solar system and the only planet we know of where life exists. Even though Earth seems extremely large to us, it is actually a tiny spec in the vast expanse of the universe. Here are 7 space facts that will make you feel very small.

1. Our sun is one of at least 100 BILLION stars, just in the Milky Way. Scientists calculate that there are at least 100 billion galaxies in the observable universe, each one brimming with stars. There are more stars than grains of sand on all of Earth’s beaches combined.

In 1995, the first planet beyond our solar system was discovered. Now, thousands of planets orbiting sun-like stars have been discovered, also known as exoplanets.

2. The Milky Way is a huge city of stars, so big that even at the speed of light (which is fast!), it would take 100,000 years to travel across it.

3. Roughly 70% of the universe is made of dark energy. Dark matter makes up about 25%. The rest — everything on Earth, everything ever observed with all of our instruments, all normal matter adds up to less than 5% of the universe.

4. If the sun were as tall as a typical front door, Earth would be the size of a nickel.

5. The sun accounts for almost all of the mass in our solar system. Leaving .2% for all the planets and everything else.

6. Edwin Hubble discovered that the Universe is expanding and that at one point in time (14 billion years ago) the universe was all collected in just one point of space.

7. Four American spacecraft are headed out of our solar system to what scientists call interstellar space. Voyager 1 is the farthest out — more than 11 billion miles from our sun. It was the first manmade object to leave our solar system. Voyager 2, is speeding along at more than 39,000 mph, but will still take more than 296,000 years to pass Sirius, the brightest star in our night sky.

Feeling small yet? Here’s a tool that will show you just how tiny we are compared to everything else out there: http://imagine.gsfc.nasa.gov/features/cosmic/earth.html

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

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allisonkitten

9 years ago

TESS: The Planet Hunter

So you’re thinking…who’s TESS? But, it’s more like: WHAT is TESS?

The Transiting Exoplanet Survey Satellite (TESS) is an explorer-class planet finder that is scheduled to launch no later than June 2018. This mission will search the entire sky for exoplanets — planets outside our solar system that orbit sun-like stars.

In the first-ever space borne all-sky transit survey, TESS will identify planets ranging from Earth-sized to gas giants, orbiting a wide range of stellar types and orbital distances.

The main goal of this mission is to detect small planets with bright host stars in the solar neighborhood, so that we can better understand these planets and their atmospheres.

TESS will have a full time job monitoring the brightness of more than 200,000 stars during a two year mission. It will search for temporary drops in brightness caused by planetary transits. These transits occur when a planet’s orbit carries it directly in front of its parent star as viewed from Earth (cool GIF below).

TESS will provide prime targets for further, more detailed studies with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future.

What is the difference between TESS and our Kepler spacecraft?

TESS and Kepler address different questions: Kepler answers “how common are Earth-like planets?” while TESS answers “where are the nearest transiting rocky planets?”

What do we hope will come out of the TESS mission?

The main goal is to find rocky exoplanets with solid surfaces at the right distance from their stars for liquid water to be present on the surface. These could be the best candidates for follow-up observations, as they fall within the “habitable zone” and be at the right temperatures for liquid water on their surface.

TESS will use four cameras to study sections of the sky’s north and south hemispheres, looking for exoplanets. The cameras would cover about 90 percent of the sky by the end of the mission. This makes TESS an ideal follow-up to the Kepler mission, which searches for exoplanets in a fixed area of the sky. Because the TESS mission surveys the entire sky, TESS is expected to find exoplanets much closer to Earth, making them easier for further study.

Stay updated on this planet-hunting mission HERE.