Venus and the Triply Ultraviolet Sun
20.08.2013

An unusual type of solar eclipse occurred last year. Usually it is the Earth's Moon that eclipses the Sun. Last June, most unusually, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun.

A Hole in Mars
1.03.2020

What created this unusual hole in Mars? The hole was discovered by chance in 2011 on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars.

Mapping Mars
19.03.1999

This month, the Mars Global Surveyor (MGS) spacecraft began its primary mission to the red planet. Orbiting about once every two hours at an altitude of over 200 miles, instruments onboard MGS now regularly explore the Martian surface and atmosphere.

ISS: Sunlight to Shadow
28.02.2008

Orbiting 400,000 kilometers above the Earth, the Moon slid into Earth's shadow to begin last week's total lunar eclipse. Of course the International Space Station (ISS) slides into Earth's shadow every 90 minutes, the time it takes it to complete one orbit at an altitude of about 400 kilometers.

A Solar Prominence Erupts in STEREO
20.10.2009

What does a solar prominence look like in three dimensions? To help find out, NASA launched the STEREO satellites to keep a steady eye on the Sun from two different vantage points. The STEREO...

Super Moon vs Micro Moon
8.09.2014

What is so super about tomorrow's supermoon? Tomorrow, a full moon will occur that appears slightly larger and brighter than usual. The reason is that the Moon's fully illuminated phase occurs within a short time from perigee - when the Moon is its closest to the Earth in its elliptical orbit.

Venus and the Triply Ultraviolet Sun
4.02.2018

An unusual type of solar eclipse occurred in 2012. Usually it is the Earth's Moon that eclipses the Sun. That year, most unusually, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun.

APOD: 2026 April 24 Б Young Moon and Sister Stars
24.04.2026

Sunlit arms of a crescent moon seem to embrace the faint lunar night side in this dramatic celestial scene from planet Earth. The single telephoto exposure tracking the sky was captured on the night of April 19, when a two day old Moon was near perigee in its elliptical orbit.

APOD: 2026 August 24 Б Comet 220P in Outburst
24.08.2026

Comet 220P is unexpectedly bright. Normally, periodic Comet 220P/McNaught is so dim that to see it requires a telescope. Two surprising outbursts this year, however, have made it about 20,000 times brighter than usual, so that it is now visible with binoculars and long-duration camera exposures.

M2-9: Wings of a Planetary Nebula
23.12.1997

Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured above, the stars transform themselves from normal stars to white dwarfs by casting off their outer gaseous envelopes.