Category Archives: Python

Map: when can you see comet PanSTARRS?

Comet C/2011 L4 (PANSTARRS) has brightened dramatically over the past week and is now visible with the naked eye from the Southern Hemisphere. Pan-STARRS is moving north rapidly and will become visible across Europe, North America and Asia from Thursday 7 March onward. The comet is expected to reach its peak brightness around the time of its closest approach to the Sun (called the perihelion) on Sunday 10 March. It may or may not lose brightness quickly afterwards, so you want to catch this comet as soon as possible!

I plotted the visibility of Pan-STARRS in the video below. Green/yellow areas in the animation indicate parts of the world where the comet will be above the horizon (and the Sun at least six degrees below the horizon). The movie shows that Pan-STARRS is only visible shortly after sunset, when it is located low above the Western horizon.

The movie was created using my Python visibility-maps module. The original frames that went into making the movie can be found here and may be used freely.


From where can you spot 2012 DA14?

On Friday 15 February, a 50-meter asteroid named 2012 DA14 will approach Earth to within a distance of just ~28 000 km. The internet is buzzing about this near-miss because the object is expected to become brighter than 9th magnitude for approximately 3 hours (18h00-21h30 UTC), peaking at a brightness of 7th magnitude near 19h45 UTC. Although this is just below the brightness limit of the unaided eye, it is within reach of good binoculars.

While there are plenty of maps online showing where in the sky you may find 2012 DA14, I could not find any maps showing where on Earth you have to be to get a good view. So I made a few maps myself. Green areas in the animated gif below indicate parts of the world where the asteroid will be above (and the Sun below) the horizon as it sweeps past. The maps were generated using a Python class which I pushed to my GitHub repository.

Visibility of 2012 DA14