For years, amateur astronomers have been waiting for a bright, naked-eye comet to pass by Earth — and finally, such an object may have arrived.
Comets are remnants from the early days of the solar system, billions of years ago. Primarily made of ice and dust, these "dirty snowballs" orbit the sun and in habit the Oort cloud, an area in the outskirts of the solar system beyond Pluto. As comets approach the inner solar system, solar wind from the sun can sweep dust back into a long tail. When these comets are close enough to Earth, they can appear as dazzling objects in the night sky. Space probes from Earth have visited several comets to learn more about their composition. Learn more about comets, icy wanderers in the solar system.
Researchers have identified nitrogen previously thought to be "missing" in comets, helping to solve a longstanding mystery about the icy space rocks.
As Rosetta's comet got near enough to the sun for frost to evaporate off its surface, a color-changing water and dust cycle began that shuffled its colors around.
Christened for months as "The Comet of the Century," Comet Kohoutek never came remotely close to living up to expectations.
A black hole was photographed, the farthest flyby was completed, and a beloved rover was proclaimed dead. Follow us through the highs and lows of 2019 space science.
As the 2010s come to a close, it's time to revisit how some of the biggest space science stories shaped the decade.
Two new "ghostly" images catch the first observed interstellar comet whizzing by the sun and in front of a distant, spiral galaxy on the object's way back out of our solar system.
Gennady Borisov stunned the astronomical community earlier this year when he announced that he had spotted an interstellar comet dashing through our solar system.
Scientists have caught their best-ever look at a comet belching out ice, dust and gas — and the observations came courtesy of a mission designed to hunt for alien worlds.
A new photo shows the solar system's second confirmed interstellar visitor in an impressive new light.
NASA's venerable Hubble Space Telescope turned its eyes to interstellar visitor Comet 2I/Borisov and caught a surprise: The interloper looks a lot like comets from our own solar system.
Observations of the interstellar Comet Borisov have been flooding in for six weeks, and the more astronomers duplicate one another's work, the more confident they are in their analysis of the object.
For the first time ever, astronomers have taken the compositional measure of an interstellar interloper.
Astronomers are only now getting the hang of spotting interstellar objects, space debris that fled another solar system to swing through ours.
A comet spotted at the end of August is officially an interstellar object, according to the International Astronomical Union.
Beginning as small, icy bodies on the outskirts of the solar system, comets turn into spectacular streaks of light when they pass through a "gateway" near Jupiter.
We could get an up-close look at our solar system's latest interstellar interloper a quarter century from now if we so desired, a new study suggests.