CMBR Dipole: Speeding Through the Universe
8.03.2008

Our Earth is not at rest. The Earth moves around the Sun. The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group of Galaxies. The Local Group falls toward the Virgo Cluster of Galaxies.

CMBR Dipole: Speeding Through the Universe
6.09.2009

Our Earth is not at rest. The Earth moves around the Sun. The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group of Galaxies. The Local Group falls toward the Virgo Cluster of Galaxies.

Comet 45P Returns
1.01.2017

An old comet has returned to the inner Solar System. Not only is Comet 45P/HondaMrkosPajduÀkovÀ physically ancient, it was first discovered 13 orbits ago in 1948. Comet 45P spends most of its time out near the orbit of Jupiter and last neared the Sun in 2011.

APOD: 2024 September 23 Á Comet Tsuchinshan ATLAS Approaches
22.09.2024

What will happen as this already bright comet approaches? Optimistic predictions have Comet C/2023 A3 (TsuchinshanÁATLAS) briefly becoming easily visible to the unaided eye -- although the future brightness of comets are notoriously hard to predict, and this comet may even break up in warming sunlight.

APOD: 2025 November 4 Á Comet Lemmon Beyond Lomnickö Peak
3.11.2025

Comet Lemmon has been putting on a show for cameras around the globe. Passing nearest to Earth in late October, the photogenic comet C/2025 A6 (Lemmon) sprouted two long and picturesque tails: a blue ion tail and a white dust tail.

M27: The Dumbbell Nebula
1.11.2016

The first hint of what will become of our Sun was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets.

Animation: Perseid Meteor Shower
7.08.2018

Where do Perseid meteors come from? Mostly small bits of stony grit, Perseid meteoroids were once expelled from Comet Swift-Tuttle and continue to follow this comet's orbit as they slowly disperse. The featured animation depicts the entire meteoroid stream as it orbits our Sun.

New Horizons at Ultima Thule
28.12.2018

When we celebrate the start of 2019, on January 1 the New Horizons spacecraft will flyby Ultima Thule. A world of the Kuiper belt 6.5 billion kilometers from the Sun, the nickname Ultima Thule (catalog designation 2014 MU69) fittingly means "beyond the known world".

Moon And Venus Share The Sky
28.07.2000

July is drawing to a close and in the past few days, some early morning risers could have looked east and seen a crescent Moon sharing the pre-dawn skies with planets Jupiter and Saturn.

Z is for Mars
22.04.2006

This composite of images spaced about a week apart - from late July 2005 (bottom right) through February 2006 (top left) - traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky. On November 7th, 2005 the Red Planet was opposite the Sun in Earth's sky (at opposition).