Everything We've Learned About Space Since You Were In School

Scientists initially observed Lucy - categorized as white dwarf star BPM 37093 (V886 Centauri) - pulsating in 1992, with its core temperature below 12,000 degrees Fahrenheit. In 1995, scientists used frequency spectra to determine Lucy's composition. They found Lucy's core mostly consisted of crystallized carbon - so in layman's terms, Lucy is a giant diamond, roughly 4,000 kilometers in diameter.

Given that it's the largest diamond in the known universe, Lucy's name was a foregone conclusion - it derives from the Beatles song, "Lucy in the Sky with Diamonds."  

Discovered in 2008, the Super Starburst Galaxy, or the Baby Boom Galaxy, is an estimated 12.3 billion light-years away and produces an average of 4,000 new stars annually. At a rate of one new star every two hours, the Baby Boom Galaxy is an enigma to NASA astronomers, who had initially observed the galaxy using the Spitzer Space Telescope. As one of many starburst galaxies found, the Baby Boom Galaxy defies conventional theories about universe expansion. Astronomers have believed galaxies form stars over long periods by merging small materials to create larger objects.

With so many stars formed in such a short period, scientists remain puzzled and may need to reevaluate their theory as they witness the "formation of one of the most massive elliptical galaxies in the universe," according to Nick Scoville of the California Institute of Technology.

Scientists have searched for proof of liquid water - the foundation for carbon-based life - on Mars for decades. In 2017, NASA researchers found evidence of tsunami activity on Mars from roughly three billion years ago, indicating the red planet may have had oceans at one time. Researchers speculate an asteroid had plummeted into a sea, causing the tsunami and shaping the planet's topography. Scientists believe the asteroid's impact created Lomonosov crater in the northern plains of Mars. 

Researchers have long speculated water once flowed on the Martian surface, and - at one point, according to NASA - "several large aquifers catastrophically ruptured," flooding the northern plains. They could find no shoreline, however, until a topographic map revealed ridge-like indents below the surface. These grooves suggest two tsunami waves formed Mars's distinct patterns. In 2017, scientists released evidence of a large lava waterfall on the planet, which they nicknamed the "Niagara Falls of Mars." It likely circled a crater in the planet's Tharsis volcanic province.

In 1995, astronomers discovered the first planet to revolve around a sun-like star. Twenty years later, the Kepler telescope detected a planet orbiting a star resembling the sun in what scientists call the "habitable zone." Since then, researchers have discovered several new planets.

In early 2017, NASA observed a group of Earth-sized, habitable-zone planets around a star called TRAPPIST-1. In November of the same year, astronomers found Ross 128b. This planet is just 11 light-years away from the Milky Way and circles a red dwarf star. In February 2018, NASA uncovered 95 new exoplanets outside of the solar system, planets with all kinds of shapes, sizes, and potential.

Discovered in 2014, Comet Lovejoy - formally known as C/2014 Q2 - passed close to the sun in January 2015. During this event, the bright comet expelled liquid at a rate of about 20 tons per second, which scientists were able to observe. According to a group of European astronomers, Comet Lovejoy released a cloud comprising alcohol, sugar, and 19 other organic molecules.

Astrophysicist Nicolas Biver told NASA that, at its peak, Comet Lovejoy discharged "as much alcohol as in at least 500 bottles of wine every second."

In 2014, Harvard astronomers discovered a mega-planet, or the Godzilla of Earths, roughly 560 light years away. The planet, also called mega-Earth and super-Earth weighs 17 times more than Earth and its diameter measures about 18,000 miles. The planet circles a sun-like planet called Draco, contained within a constellation formed about three billion years after the Big Bang. Labeled Kepler-10c, the exoplanet is rocky and solid, which surprised scientists who thought it would be gaseous, similar to Jupiter.

Any oxygen and water on Kepler-10c's heavy atmosphere can immediately turn into a solid substance, rendering the exoplanet inhospitable.