Our Sun

All the planets, moons, and smaller things in the solar system are just dust, compared to the star that they orbit; the Sun contains 99.9% of the mass of the solar system. We think of it as our source of light, but it doesn't just emit photons. The solar wind blasts fast-moving electrons, protons, and highly ionized atoms in all directions, a constant stream punctuated by ferocious coronal mass ejections. The solar wind carries with it a magnetic field wound into a tight spiral by the Sun's rotation.

The solar wind pushes outward against the interstellar medium, penning the solar system inside a bubble called the "heliosphere" that's at least 200 AU across. The twin Voyager spacecraft are now probing the heliosphere's edges. Closer to home, a fleet of spacecraft monitors the space weather generated by the Sun, warning us of its effects on Earth, from the benevolent (aurorae) to the potentially disastrous (irradiation of astronauts and damage to communications satellites and power grids). Currently operating solar space observatories include ACE, GGS, WIND, Hinode, PICARD, RHESSI, SOHO, SDO, Solar Monitoring Observatory, and STEREO.

Latest Blog Entries about the Sun, Heliosphere, and Space Weather

Full Free Intro Astronomy Class Now Online

Posted by Bruce Betts on 2012/05/22 02:57 CDT

Bruce Betts' complete CSUDH Intro Astronomy and Planetary Science class is now available online. Find out how to access it, and go behind the scenes.

From the 2011 Fall Meeting of the American Geophysical Union (AGU): Voyager 1 at the edge of the solar system

Posted by Emily Lakdawalla on 2011/12/05 04:13 CST

A report on a press briefing about Voyager 1 at the Fall 2011 American Geophyisical Union meeting. The spacecraft has entered a new region between our solar system and interstellar space, which scientists are calling the stagnation region.

Transit of Deimos, Curiosity sol 42 (aligned)

Curiosity catches sunspots along with Phobos and Deimos transits

Posted by Emily Lakdawalla on 2012/10/03 07:15 CDT | 2 comments

Curiosity has been shooting photos of the Sun as Phobos and Deimos cross its face, and -- as far as I can tell -- captured sunspots as well.

Cool video: Jupiter, its moons, a comet, and...the Sun?

Posted by Emily Lakdawalla on 2012/05/16 11:45 CDT | 1 comments

Here's a neat video posted by SungrazerComets (the Twitter identity of the U.S. Naval Research Laboratory's Sungrazing Comets website) this morning. It's an animation of images taken by the Solar and Heliospheric Observatory (SOHO) on May 13 and 14, when Jupiter was passing through solar conjunction