Hammer Versus Feather on the Moon
1.11.2011

If you drop a hammer and a feather together, which reaches the ground first? On the Earth, it's the hammer, but is the reason only because of air resistance? Scientists even before Galileo have pondered and tested this simple experiment and felt that without air resistance, all objects would fall the same way.

NGC 1898: Globular Cluster in the LMC
3.10.2018

Jewels don't shine this bright -- only stars do. And almost every spot in this glittering jewel-box of an image from the Hubble Space Telescope is a star. Now some stars are more red than our Sun, and some more blue -- but all of them are much farther away.

Starburst Galaxy M94 from Hubble
31.07.2022

Why does this galaxy have a ring of bright blue stars? Beautiful island universe Messier 94 lies a mere 15 million light-years distant in the northern constellation of the Hunting Dogs (Canes Venatici).

APOD: 2023 May 23 Б Jupiters Swirls from Juno
23.05.2023

Big storms are different on Jupiter. On Earth, huge hurricanes and colossal cyclones are centered on regions of low pressure, but on Jupiter, it is the high-pressure, anti-cyclone storms that are the largest. On Earth, large storms can last weeks, but on Jupiter they can last years.

Stickney Crater
8.07.2023

Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet's moons in 1877.

APOD: 2025 June 10 Б Enceladus in True Color
10.06.2025

Do oceans under the ice of Saturn's moon Enceladus contain life? A reason to think so involves long features -- some dubbed tiger stripes -- that are known to be spewing ice from the moon's icy interior into space.

AB Aurigae: How To Make Planets
11.06.1999

This enhanced Hubble Space Telescope image shows in remarkable detail the inner portion of the disk of dust and gas surrounding the star AB Aurigae. Knots of material, visible here for the first time...

Mars: The View from HiRISE
10.04.2006

HiRISE - the High Resolution Imaging Science Experiment - rides on the Mars Reconnaissance Orbiter (MRO)spacecraft just arrived in Mars orbit on March 10. This sharp view of the martian surface from the HiRISE camera includes image data with a full resolution of about 2.5 meters per pixel - recorded from a range of 2,500 kilometers.

A Beautiful Boomerang Nebula
28.12.2007

This symmetric cloud dubbed the Boomerang Nebula was created by a high-speed wind of gas and dust blowing from an aging central star at speeds of nearly 600,000 kilometers per hour. The rapid...

Ancient Craters of Southern Rhea
13.05.2008

Saturn's ragged moon Rhea has one of the oldest surfaces known. Estimated as changing little in the past billion years, Rhea shows craters so old they no longer appear round their edges have become compromised by more recent cratering.