APOD: 2024 September 8 Б M31: The Andromeda Galaxy
8.09.2024

The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy. Even at some two and a half million light-years distant, this immense spiral galaxy -- spanning over 200,000 light years -- is visible, although as a faint, nebulous cloud in the constellation Andromeda.

Sand Dunes on Mars
26.02.2001

Sand dunes on Mars can appear exotic. The dark dunes above might be compared to shark's teeth or chocolate confections. In reality, they arise from the complex relationship between the sandy surface and high winds on Mars.

A Perseid Meteor
11.08.1997

Tonight the Perseid Meteor Shower reaches its maximum. Grains of rocky ice will streak across the sky as they evaporate during entry into Earth's atmosphere. These ice chips were shed from Comet Swift-Tuttle. The Perseids result from the annual crossing of the Earth through Comet Swift-Tuttle's orbit.

Comet Machholz in View
5.01.2005

Good views of Comet Machholz are in store for northern hemisphere comet watchers in January. Now making its closest approach to planet Earth, the comet will pass near the lovely Pleiades star cluster on January 7th and the double star cluster in Perseus on January 27th as Machholz moves relatively quickly through the evening sky.

Dust Mountains in the Carina Nebula
7.10.2008

Bright young stars sometimes sculpt picturesque dust mountains soon after being born. Created quite by accident, the energetic light and winds from these massive newborn stars burn away accumulations of dark dust and cool gas in a slow but persistent manner.

Sunset at the Portara
20.03.2009

Today, the Sun crosses the celestial equator heading north at 11:44 UT. Known as an equinox, this astronomical event marks the first day of spring in the northern hemisphere and autumn in the south. It also marks the beginning of Norouz, the Persian (Iranian) new year. Equinox means equal night.

Shadows of Saturn at Equinox
1.09.2009

Unusual shadows and dark rings appeared around Saturn near its equinox last month. At that time -- early August -- Saturn's ring plane pointed directly at the Sun. Visible above, Saturn's moon Tethys casts a shadow visible only on the far right.

NGC 7822 in Cepheus
22.10.2010

Pillars of gas, dust, and young, hot stars seem to fill the gaping maw of NGC 7822. At the edge of a giant molecular cloud toward the northern constellation Cepheus, the glowing star forming region lies about 3,000 light-years away. Within the nebula, bright edges and dark shapes are highlighted in this colorful skyscape.

Decorating the Sky
25.12.2010

Bright stars, clouds of dust and glowing nebulae decorate this cosmic scene, a skyscape just north of Orion's belt. Close to the plane of our Milky Way Galaxy, the wide field view spans about 5.5 degrees. Striking bluish M78, a reflection nebula, is at the left.

Airglow over Italy
6.09.2012

In this serene night skyscape, the Milky Way's graceful arc stretches over prominent peaks in the Italian Alps known as Tre Cime di Lavaredo. A 180 degree wide-angle panorama made in four exposures on August 24, the scene does look to the north and the sky is suffused with an eerie greenish light.