A large snowball has just passed the Earth. Known as Comet 45P/Honda–Mrkos–Pajdušáková", or 45P for short, the comet came 10 times closer to Earth yesterday than the Earth ever gets to the Sun. During this passage, the comet was photographed sporting a thin ion tail and a faint but expansive green coma. The green color is caused mostly by energized molecules of carbon. Comet 45P became just bright enough to see with the unaided eye when it came closest to the Sun in December. Now, however, the comet is fading as it heads back out to near the orbit of Jupiter, where it spends most of its time. The kilometer-sized nucleus of ice and dirt will return to the inner Solar System in 2022.
Seven Earth-like planets have been found orbiting a sun not too far — in space terms, at least — from our own.
Wednesday that the planets resemble Earth in composition and spacing
from their star, which means their conditions might be favorable to
liquid water and life, Time reported.
“The planets form a very compact system,” Michaël Gillon of
Belgium’s University of Liège, said in a
teleconference, according to Time. “They are very close to their
star and are reminiscent of the system of moons that orbit Jupiter. They
could have liquid water and life.”
Astronomers studied the star, Trappist-1 — which, at 39
light years away from Earth, is considered a relative neighbor — for six
years, using telescopes located all over the world, plus the Spitzer
Space Telescope. Read more (2/22/17 2:04 PM)
A small, faint star relatively close by is home to seven Earth-size planets with conditions that could be right for liquid water and maybe even life.
The discovery sets a record for both the most Earth-size planets and the most potentially habitable planets ever discovered around a single star.
The strange planetary system is quite compact, with all of these worlds orbiting their star closer than Mercury orbits the sun, according to a newly published report in Nature.
“If you were on the surface of one of these planets, you would see the other ones as we see the moon, or a bit smaller,” says Michaël Gillon, an astronomer at the University of Liège in Belgium. “The view would be very impressive.”