By Amanda Barnett, CNN

Comet ISON may put on a show when it skims through the sun's atmosphere later this year. Right now, it's still far away, but we're keeping track and will give you regular updates. Here are five key facts about ISON as we await its arrival:

What's with the funky name?

Comet ISON was discovered by Russian astronomers Vitali Nevski and Artyom Novichonok in September 2012. It's named after their night-sky survey program, the International Scientific Optical Network, a group of observatories in 10 countries organized to track objects in space.

FULL STORY

By Amanda Barnett, CNN

A rare treat for sky watchers is hovering overhead.

Comet Pan-STARRS is now visible on the western horizon in the Northern Hemisphere and viewers in the United States may be able to see it with the naked eye.

The comet has been visible through telescopes in the Southern Hemisphere for a while and amateur photographers are now posting sightings online from the Northern Hemisphere.

Scientists estimate that naked-eye comets happen only once every five to 10 years, according to the Jet Propulsion Laboratory.

FULL POST

By Amanda Barnett, CNN

First a meteor exploded over Russia, followed closely by an asteroid fly-by. Now, two comets are expected to put on a naked-eye spectacle for sky watchers in the Northern Hemisphere.

Up first is Comet Pan-STARRS, which gets its funky name from the telescope credited with discovering it in June 2001: the Panoramic Survey Telescope & Rapid Response System in Hawaii.

The comet is already visible through telescopes in the Southern Hemisphere, and it should swing into view over the Northern Hemisphere beginning around March 8.

FULL STORY

Vesta, the second-largest object in our solar system's asteroid belt, is a protoplanet, according to research released Thursday. Scientists reviewed data from the Dawn spacecraft orbiting Vesta and concluded that Vesta is protoplanet that survived numerous collisions with other space rocks since it formed more than 4.5 billion years ago.

"Dawn’s mission at Vesta has been a spectacular success. It’s transformed Vesta from a fuzzy orb into a planetary body," said Carol Raymond, the deputy principal investigator for Dawn at NASA's Jet Propulsion Laboratory in Pasadena, California.

Becoming a protoplanet is an upgrade from Vesta’s previous designation as an asteroid or minor planet. It means Vesta’s structure shows it has a dense, layered body and orbits the sun, like the Earth and other rocky planets. Vesta didn’t quite make it to full-fledged planet, but Raymond said it's more like a planet than an asteroid.

FULL POST

For the first time, light coming directly from a “super-Earth” planet outside our solar system has been detected.

NASA’s Spitzer Space Telescope spotted the light shining from 55 Cancri e, a massive, scorching hot planet located about 41 light years away.

Super-Earths are up to 10 times more massive than our Earth, but lighter than gas giants like Neptune, NASA says. They can be made of gas, rock or a combination of both. Some scientists believe super-Earths have a better chance of being habitable than planets closer to the size of Earth.

Super-Earth 55 Cancri was discovered in 2004. Spitzer and other telescopes already have recorded how light from the planet changed as it passed in front of its star. In the new study, Spitzer measured how much infrared light comes from the planet itself.

The new data indicates the planet is probably dark, and that its sun-facing side is more than 3,140 degrees Fahrenheit (2,000 Kelvin), hot enough to melt metal. NASA says the new information is consistent with an earlier theory that 55 Cancri has a rocky core wrapped in a layer of water (both liquid and gas). The planet is believed to be topped by a blanket of steam.

NASA says in a statement that Spitzer's discovery is historic and will help in the search for life on other planets.

"Spitzer has amazed us yet again," said Bill Danchi, a NASA Spitzer program scientist in Washington. "The spacecraft is pioneering the study of atmospheres of distant planets and paving the way for NASA's upcoming James Webb Space Telescope to apply a similar technique on potentially habitable planets."

The James Webb Space Telescope is scheduled to launch in 2018 and scientists hope it will be able to reveal even more about 55 Cancri’s composition.

NASA’s biggest and most advanced Mars rover blasted off Saturday from Cape Canaveral, Florida.

Curiosity is packed with 10 science experiments to determine whether Mars has ever been suitable for life and to find clues about past life forms that may have been preserved in rocks. NASA says Curiosity won’t answer the age-old questions about life on Mars, but it will provide important information that will guide future missions.

Searching for life on Mars

The spacecraft sent a signal after separation from the rocket, NASA said.

The launch was originally scheduled for Friday, but the mission team took an extra day to remove and replace a flight termination system battery, NASA said.

FULL POST