Comet

Discovering the first true "alien Earth" is a long-held dream of astronomers — and recent exoplanet discoveries have shown that small, rocky worlds like our own are abundant in the galaxy. Let’s look at some of the closest known analogues to our home planet.

NASA's Kepler Space Telescope was an observatory in space dedicated to finding planets outside our solar system, with a particular focus on finding planets that might resemble Earth.

NASA's Curiosity rover is currently roaming Mars' landscape looking for signs of life and learning about the Red Planet's unique environment. Curiosity has four main science goals: Determine whether life ever arose on Mars. Characterize the climate of Mars. Characterize the geology of Mars. Prepare for human exploration.

Remote sensing is the acquiring of information from a distance. NASA observes Earth and other planetary bodies via remote sensors on satellites and aircraft that detect and record reflected or emitted energy.

Quasars are distant objects powered by black holes a billion times as massive as our sun, Shining so brightly that they eclipse the ancient galaxies that contain them. These powerful dynamos have fascinated astronomers since their discovery half a century ago.

Asteroids are rocky objects revolving around the sun that are too small to be called planets. They are also known as planetoids or minor planets. There are millions of asteroids, ranging in size from hundreds of miles to several feet across.

Comets are cosmic snowballs of frozen gases, rock, and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet's orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets. The dust and gases form a tail that stretches away from the Sun for millions of miles.

Everywhere we point telescopes in the sky, we see galaxies, going back to the earliest moments in history where galaxies could even exist. These galaxies fall into a pattern: large scale structure of the Universe.

Astrophysical fluid dynamics is a modern branch of astronomy involving fluid mechanics which deals with the motion of fluids, like the gases which the stars are made up of or any fluid which is found in outer space.

The sky above us is strewn with alluringly beautiful remnants of ancient supernovae, that is, stars that lived out their lives and then died in these violent explosions. A supernova is a name given to the cataclysmic explosion of a massive star at the end of its life.