A Backward Sunspot and the New Solar Cycle
30.08.2006

Why is sunspot 905 backwards? Perhaps it is a key marker for the beginning of a new magnetic cycle on our Sun. Every 11 years, our Sun goes through a magnetic cycle, at the end of which its overall magnetic orientation is reversed.

APOD: 2024 December 22 Б The Local Fluff
22.12.2024

The stars are not alone. In the disk of our Milky Way Galaxy, about 10 percent of visible matter is in the form of gas called the interstellar medium (ISM). The ISM is not uniform and shows patchiness even near our Sun.

Layers of a Total Solar Eclipse
27.09.2017

Neither rain, nor snow, nor dark of night can keep a space-based spacecraft from watching the Sun. In fact, from its vantage point 1.5 million kilometers sunward of planet Earth, NASA's SOlar Heliospheric Observatory (SOHO) can always monitor the Sun's outer atmosphere, or corona.

Aurorae and Lightning on Jupiter
24.03.2021

Why does so much of Jupiter's lightning occur near its poles? Similar to Earth, Jupiter experiences both aurorae and lightning. Different from Earth, though, Jupiter's lightning usually occurs near its poles -- while much of Earth's lightning occurs near its equator.

The Brightest Spot on Ceres
11.12.2015

Dwarf planet Ceres is the largest object in the Solar System's main asteroid belt with a diameter of about 950 kilometers. Exploring Ceres from orbit since March, the Dawn spacecraft's camera...

Sungrazer
22.03.2009

The Sun destroyed this comet. Arcing toward a fiery fate, this Sungrazer comet was recorded by the SOHO spacecraft's Large Angle Spectrometric COronagraph(LASCO) on 1996 Dec. 23. LASCO uses an occulting disk...

Clusters, Hartley, and the Heart
14.10.2010

An alluring Comet Hartley 2 cruised through planet Earth's night sky on October 8, passing within about a Full Moon's width of the famous double star cluster in Perseus. The much anticipated...

Hartley 2 Star Cluster Tour
2.12.2010

Early in November, small but active Comet Hartley 2 (103/P Hartley) became the fifth comet imaged close-up by a spacecraft from planet Earth. Continuing its own tour of the solar system with a 6 year orbital period, Hartley 2 is now appearing in the nautical constellation Puppis.

Man Enters Space
14.04.2001

Forty years ago, on April 12, 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human in space. His remotely controlled Vostok 1 spacecraft lofted him to an altitude of 200 miles and carried him once around planet Earth. Gagarin was strictly a passenger on this flight.

Dark Terrain on Saturn s Iapetus
3.01.2006

Why are vast sections of Iapetus as dark as coal? No one knows for sure. Iapetus, the third largest moon of Saturn, was inspected again as the Saturn-orbiting robot Cassini spacecraft swooped past the enigmatic world again late last year.