Comets Bradfield and LINEAR Rising
3.05.2004

Comet Bradfield is easy to see on the left, but can you find Comet LINEAR on the right? Last week, just before sunrise from the northern hemisphere, two bright comets were visible in the same part of the sky at the same time.

The Tails of Comet NEAT Q4
12.05.2004

Comet NEAT (Q4) is showing its tails. As the large snowball officially dubbed Comet C/2001 Q4 (NEAT) falls toward the inner Solar System, it has already passed the Earth and will reach its closest approach to the Sun this coming Saturday.

Afternoon Analemma
23.09.2023

An analemma is that figure-8 curve you get when you mark the position of the Sun at the same time each day for one year. To make this one, a 4x5 pinhole camera was set up looking north in southern New Zealand skies.

SWAN Meets Galaxy
19.10.2006

This cosmic portrait recorded October 9th features the lovely blue-green coma of Comet SWAN posing with spiral galaxy NGC 5005 in the northern constellation Canes Venatici. At the time the comet (center) was in the close foreground, a mere 9 light-minutes from planet Earth, with the galaxy a more substantial 60 million light-years distant.

CMBR Dipole: Speeding Through the Universe
9.03.2008

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
2.01.2017

An old comet has returned to the inner Solar System. Not only is Comet 45P/HondaMrkosPajduАkovА 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 Б Comet Tsuchinshan ATLAS Approaches
23.09.2024

What will happen as this already bright comet approaches? Optimistic predictions have Comet C/2023 A3 (TsuchinshanБATLAS) 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 Б Comet Lemmon Beyond Lomnickц Peak
4.11.2025

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
2.11.2016

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.