The Space Station Crosses a Spotless Sun
28.10.2019

Typically, the International Space Station is visible only at night. Slowly drifting across the night sky as it orbits the Earth, the International Space Station (ISS) can be seen as a bright spot about once a month from many locations.

Arp 273: Battling Galaxies from Hubble
20.11.2019

What's happening to these spiral galaxies? Although details remain uncertain, there sure seems to be a titanic battle going on. The upper galaxy is labelled UGC 1810 by itself, but together with its collisional partners is known as Arp 273.

APOD: 2024 March 12 Б A Galaxy Shaped Rocket Exhaust Spiral
12.03.2024

What's that over the horizon? What may look like a strangely nearby galaxy is actually a normal rocket's exhaust plume -- but unusually backlit. Although the SpaceX Falcon 9 rocket was launched from...

COBE Hotspots: The Oldest Structures Known
7.02.1998

Above is a microwave image of the entire sky. The plane of our galaxy runs horizontally through the center. This historic all-sky map is based on the first two years of data from NASA's COsmic Background Explorer (COBE) satellite.

Gravity Probe B Confirms the Existence of Gravitomagnetism
10.05.2011

Does gravity have a magnetic counterpart? Spin any electric charge and you get a magnetic field. Spin any mass and, according to Einstein, you should get a very slight effect that acts something like magnetism. This effect is expected to be so small that it is beyond practical experience and ground laboratory measurement.

NGC 5078 and Friends
25.05.2016

This sharp telescopic field of view holds two bright galaxies. Barred spiral NGC 5101 (top right) and nearly edge-on system NGC 5078 are separated on the sky by about 0.5 degrees or about the apparent width of a full moon.

Geostationary Highway through Orion
16.01.2017

Put a satellite in a circular orbit about 42,000 kilometers from the center of the Earth and it will orbit once in 24 hours. Because that matches Earth's rotation period, it is known as a geosynchronous orbit.

Solar Wind And Milky Way
4.03.1997

The Sun is bright, so bright that it overwhelms the light from other stars even for most satellite-borne telescopes. But LASCO, a coronograph onboard the space-based SOHO Observatory, uses occulting disks to block the intense solar light and examine the tenuous, hot gases millions of miles above the Sun's surface.

Three Month Composite of Comet Holmes
5.02.2008

How has Comet Holmes changed? Since brightening unexpectedly by nearly one million fold in late October, the last three months have found the coma of Comet 17P/Holmes both expanding and fading. This spectacular composite image shows how the coma and tail of Comet Holmes have changed.

Stars and Dust Across Corona Australis
27.06.2011

Cosmic dust clouds sprawl across a rich field of stars in this sweeping telescopic vista near the northern boundary of Corona Australis, the Southern Crown. Probably less than 500 light-years away and effectively blocking...