ESO; (inset) J. F. Lestrade et al., Astronomy & Astrophysics (22 November)

ScienceShot: Nearby Solar System Looks More Like Home

Gliese 581 (main image) is a red dwarf star just 21 light-years from Earth that boasts a number of planets. As astronomers report this month in Astronomy & Astrophysics, the Herschel Space Observatory has now discovered another feature that earthlings would find familiar: a ring of dust far from the star which resembles the Edgeworth-Kuiper belt, a zone of objects, each much smaller than Earth, that lies beyond Neptune's orbit and includes Pluto. The dim red star's light heats dust in the belt, which emits the far-infrared wavelengths that Herschel detects (inset). The newfound debris disk is about as large as the Edgeworth-Kuiper belt, even though Gliese 581 is small and all of its known planets lie closer to their sun than Earth does to ours. The scientists speculate that the little red star harbors a more remote planet whose gravity stirs up the belt's small objects, causing them to collide and spew the dust that Herschel has discerned.

See more ScienceShots.