Southern Sky Notes

From the sky archive · Comets

Comet NEAT (C/2002 V1) in the March 2003 twilight

First posted March 2003; rewritten 11 October 2026

This page first went up in March 2003 while Comet NEAT was in our evening sky. It has been rewritten as a record of that comet and a guide to spotting comets low in twilight.

A close pass by the Sun

Comet C/2002 V1 (NEAT) was found in November 2002 by the Near-Earth Asteroid Tracking programme, an automated survey run by NASA's Jet Propulsion Laboratory. Its orbit took it very close to the Sun: at perihelion in mid-February 2003 it passed roughly a tenth of Earth's distance from the Sun, well inside the orbit of Mercury.

Around perihelion the comet was lost in the Sun's glare from the ground, but the SOHO spacecraft's coronagraph, which blocks out the solar disc, captured it brightening dramatically with a long, bright tail. Those images were widely shared and remain some of the best-known pictures of a comet close to the Sun.

Low in the March evening sky

After perihelion the comet moved away from the Sun and into southern evening skies. In early March 2003 it could be found from New Zealand low in the west after sunset, in bright twilight. It had faded from its peak and was a modest binocular object with a short tail, but it was a good example of how the southern hemisphere sometimes gets the best post-perihelion view of a comet.

How comets are named

Comet names have two parts: a designation and a discoverer's name.

  • The prefix shows the type. C/ is a non-periodic comet (a period over 200 years, or none), P/ a periodic comet, and D/ one that has broken up or been lost.
  • The year of discovery comes next.
  • A letter marks the half-month of discovery: A for 1-15 January, B for 16-31 January, and so on through the year, skipping I. V is 1-15 November.
  • A number gives the order of discovery in that half-month.

So C/2002 V1 was the first non-periodic comet reported in the first half of November 2002. The name in brackets credits the discoverer, here the NEAT survey. Many recent comets carry survey names such as ATLAS, PANSTARRS or ZTF.

Finding a low twilight comet

Comets near the Sun are often only visible low in twilight, which is a difficult combination. Tips:

  1. Get a clear, flat horizon in the right direction: west after sunset, east before dawn. A beach or hilltop is ideal.
  2. Know the timing. Start looking 30 to 60 minutes after sunset (or before sunrise). Too early and the sky is too bright; too late and the comet has set.
  3. Use binoculars. Sweep slowly back and forth above the horizon. A comet looks like a small fuzzy patch, often with a short tail pointing away from the Sun.
  4. Use a nearby bright planet or star as a guide if one is in the same part of the sky.
  5. Never sweep with binoculars or a telescope while any part of the Sun is above the horizon.
  6. Try the camera. A phone or camera on a tripod often shows a faint twilight comet before your eye finds it.

For background on what comets are and where they come from, NASA's comets overview is a good start. The following year brought a much easier comet; see Comet C/2001 Q4 (NEAT) in May 2004.