Double Trouble Solar Bubbles
16.05.2002

During April and May, attention has been focused on the western evening sky, presenting its spectacle of bright planets and crescent moons shortly after sunset. Meanwhile, the Sun itself has not been just sinking quietly below the horizon.

Aristarchus Plateau
13.09.2002

Anchored in the vast lava flows of the Moon's Oceanus Procellarum lies the Aristarchus Plateau. Recorded from a backyard observatory on planet Earth, this sharp, amazingly colorful view nicely captures the geologically diverse area, including the brownish plateau, Aristarchus and Herodotus craters, and the meandering Vallis Schroteri.

Mimas: Small Moon with a Big Crater
21.10.2014

Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn's smallest moons. The crater, named Herschel after the 1789 discoverer of Mimas, Sir William Herschel, spans about 130 kilometers and is pictured above.

Perseids and MAGIC
11.08.2022

On August 11, 2021 a multi-mirror, 17 meter-diameter MAGIC telescope reflected this starry night sky from the Roque de los Muchachos European Northern Observatory on the Canary Island of La Palma. MAGIC stands for Major Atmospheric Gamma Imaging Cherenkov.

Mariner's Mercury
6.09.1998

Mercury, the closest planet to the Sun, remains the most mysterious of the Solar System's inner planets. Hiding in the Sun's glare it is a difficult target for Earth bound observers.

Jagged Hills on Jupiters Callisto
28.08.2001

Why does Jupiter's moon Callisto have unusual jagged hills? This mystery came to light after the robot spacecraft Galileo, in orbit around Jupiter since 1995, swooped past the dark moon in May. The resulting pictures were the highest resolution yet obtained for a Jovian moon: objects as small as 3 meters across are discernable.

A Spectacular Rayed Crater on Mercury
3.11.2008

Why does Mercury have so many rayed craters? No one is sure. The robotic MESSENGER spacecraft that is taking unprecedented images as it swoops past the innermost planet has provided dramatic confirmation that Mercury has more rayed craters than Earth's Moon.

Global Warming Predictions
21.04.2009

How much will the Earth's surface warm up over the lives of our children? No one is sure. Compared to the past 100 million years, the Earth is currently enduring a relative cold spell, possibly about four degrees Celsius below average.

APOD: 2023 September 19 Б HH 211: Jets from a Forming Star
19.09.2023

Do stars always create jets as they form? No one is sure. As a gas cloud gravitationally contracts, it forms a disk that can spin too fast to continue contracting into a protostar. Theorists hypothesize that this spin can be reduced by expelling jets.

Spirit s 3D View Towards Sleep Hollow
6.01.2004

Working late, tired mission members nicknamed the smooth-looking depression to the left of center in this image from the martian surface, Sleepy Hollow. The picture is a portion of the 3D panorama of the Spirit rover's landing site released yesterday, constructed with data from the Mars rover's navigation cameras.