Mars Approach 2020
6.10.2020

Look to the east just after sunset tonight and you'll see a most impressive Mars. Tonight, Mars will appear its biggest and brightest of the year, as Earth passes closer to the red planet than it has in over two years -- and will be again for another two years.

A Filament Leaps from the Sun
8.11.2021

Why, sometimes, does part of the Sun's atmosphere leap into space? The reason lies in changing magnetic fields that thread through the Sun's surface. Regions of strong surface magnetism, known as active regions, are usually marked by dark sunspots.

APOD: 2024 May 11 Б AR 3664: Giant Sunspot Group
11.05.2024

Right now, one of the largest sunspot groups in recent history is crossing the Sun. Active Region 3664 is not only big -- it's violent, throwing off clouds of particles into the Solar System. Some of these CMEs are already impacting the Earth, and others might follow.

Venus and Mercury at Sunset
14.01.2015

Inner planets Venus and Mercury can never wander far from the Sun in Earth's sky. This week you've probably seen them both gathered near the western horizon just after sunset, a close conjunction of bright celestial beacons in the fading twilight.

Asteroids in the Distance
6.03.2011

Rocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily. Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-balls streak through our atmosphere daily, most evaporating quickly to nothing.

APOD: 2025 June 21 Б Two Worlds, Two Analemmas
21.06.2025

Sure, that figure-8 shaped curve you get when you mark the position of the Sun in Earth's sky at the same time each day over one year is called an analemma.

Three Years of Saturn
7.04.2007

Using an image recorded just last month as a base, this composite illustration tracks the motion of bright Saturn as it wanders through planet Earth's night sky. Starting at the upper right, Saturn's position is shown about every two weeks beginning in August 2005 and projected through September 2008.

Eclipse Over New York
4.11.2013

A sunrise over New York City rarely looks like this. Yesterday, however, the Sun rose partly eclipsed by the Moon as seen from much of the eastern North American and northern South America. Simultaneously, much of Africa, already well into daytime, saw the eclipse from beginning to end.

A Martian Autumn Begins
23.09.1997

Today is the first day of Autumn in the Northern Hemisphere of Planet Earth. The Autumnal Equinox occured yesterday at 7:56 pm EDT as the Sun crossed the celestial equator from North to South.

Comet NEAT in Southern Skies
6.03.2003

After last month's dramatic swoop past the Sun, Comet NEAT (C/2002 V1) appeared as a naked-eye comet, emerging from the evening twilight in planet Earth's southern skies. On March 1st, New Zealand...