Gliese 876 System Includes Large Terrestrial Planet
14.06.2005

Is our Earth unique? In continuing efforts to answer this question, astronomers have now discovered an Earth-like planet orbiting a distant normal star. Previously over 150 gas-giant planets like Jupiter had been so discovered.

An Anomalous SETI Signal
6.03.2004

No one knows for sure what caused this signal. There is a slight possibility that it just might originate from an extraterrestrial intelligence. The bright colors on the blue background indicate that an anomalous signal was received here on Earth by a radio telescope involved in a Search for Extraterrestrial Intelligence (SETI).

Southwest Mercury
12.02.2000

The planet Mercury resembles a moon. Mercury's old surface is heavily cratered like many moons. Mercury is larger than most moons but smaller than Jupiter's moon Ganymede and Saturn's moon Titan. Mercury is much denser and more massive than any moon, though, because it is made mostly of iron.

Tails of Comet Garradd
20.10.2011

A good target for binoculars and small telescopes, Comet Garradd (C/2009 P1) now shines in planet Earth's evening skies, a steady performer but just below naked-eye visibility. Telescopic images like this composite from...

Mercurys Transit: An Unusual Spot on the Sun
24.08.2014

What's that dot on the Sun? If you look closely, it is almost perfectly round. The dot is the result of an unusual type of solar eclipse that occurred in 2006. Usually it is the Earth's Moon that eclipses the Sun. This time, the planet Mercury took a turn.

Summer Planets and Milky Way
22.07.2016

Lights sprawl toward the horizon in this night skyscape from Uludag National Park, Bursa Province, Turkey, planet Earth. The stars and nebulae of the Milky Way are still visible though, stretching above the lights on the northern summer night while three other planets shine brightly.

Road to Mars
8.07.2018

What's that light at the end of the road? Mars. This is a good month to point out Mars to your friends and family because our neighboring planet will not only be its brightest in 15 years, it will be visible for much of night.

Perseids from Perseus
9.08.2020

Where are all these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaks tomorrow night is known as the Perseids -- the meteors all appear to came from a radiant toward Perseus.

APOD: 2023 December 17 Б Geminids over Chinas Nianhu Lake
16.12.2023

Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids -- because shower meteors all appear to come from a radiant toward Gemini.

Phobos: Moon over Mars
21.03.2024

A tiny moon with a scary name, Phobos emerges from behind the Red Planet in this timelapse sequence from the Earth-orbiting Hubble Space Telescope. Over 22 minutes the 13 separate exposures were captured near the 2016 closest approach of Mars to planet Earth. Martians have to look to the west to watch Phobos rise, though.