Highlights of the Summer Sky
5.06.2017

What's up in the sky this summer? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early summer sky events fan out toward the left, while late summer events are projected toward the right.

Highlights of the North Spring Sky
13.03.2019

What can you see in the night sky this season? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) spring sky events fan out toward the left, while late spring events are projected toward the right.

Highlights of the Summer Sky
27.06.2018

What can you see in the night sky this summer? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) summer sky events fan out toward the left, while late summer events are projected toward the right.

Cancri 55 e: Climate Patterns on a Lava World
5.04.2016

Why might you want to visit super-earth Cancri 55 e? Its extremely hot climate would be a deterrent, as mornings on this world might bring fresh lava flows. Discovered in 2004, the planet Cancri 55 e has twice the diameter of our Earth and about 10 times Earth's mass.

Mars Rising Behind Poodle Rock
13.08.2003

Have you seen Mars lately? As Earth and Mars near their closest approach in nearly 60,000 years on August 27, the red planet has begun to appear dramatically bright and show interesting details through telescopes and binoculars. Although not yet visible at sunset, Mars can be seen rising increasingly earlier in the evening.

Distant Neutrinos Detected Below Antarctic Ice
1.09.2015

From where do these neutrinos come? The IceCube Neutrino Observatory near the South Pole of the Earth has begun to detect nearly invisible particles of very high energy. Although these rarely-interacting neutrinos pass through much of the Earth just before being detected, where they started remains a mystery.

Andromeda on the Rocks
27.09.2013

How far can you see? The Andromeda Galaxy 2.5 million light years away is the most distant object easily seen by the unaided eye. Other apparent denizens of the night sky, stars, clusters...

The Full Moon
19.04.1999

Earth has one moon. A symbol in famous love songs, movies, poems, and folklore, many myths about the Moon date back to ancient history. In fact, the name Monday originates from Moon-day. The Moon glows by light it reflects from the Sun and is frequently the brightest object in the night sky.

APOD: 2024 January 8 Б The Phases of Venus
8.01.2024

Venus goes through phases. Just like our Moon, Venus can appear as a full circular disk, a thin crescent, or anything in between. Venus, frequently the brightest object in the post-sunset or pre-sunrise sky, appears so small, however, that it usually requires binoculars or a small telescope to clearly see its current phase.

A Cosmic Snowball
30.05.1997

Like cosmic snowballs, fluffy comet-like objects the size of houses and composed mostly of water-ice, may be pummeling planet Earth 5 to 30 times a minute. This controversial theory was originally proposed in 1986 by Dr. Louis Frank (U. Iowa) based on data from NASA's Dynamics Explorer 1.