The Hubble eXtreme Deep Field

Figure 1. The Hubble eXtreme Deep Field (XDF).

This image is the Hubble eXtreme Deep Field (XDF). It was created by combining many images taken between 2002 and 2012 by the Hubble Space Telescope. The total exposure time was 22.5 days (almost 2 million seconds), and the image contains… read more


Submitted on 8 June 2015

If You See a Fireball, Please Report It

Figure 2. Sightings of a single fireball that appeared on 2015-03-15.

If you have ever seen a fireball, which is an unusually bright meteor (or shooting star), then you know that they can be very impressive. But did you also know that reporting your observation can help to further science? Fireballs, and meteors in general, are like… read more

Submitted on 21 March 2015

New Horizons

Figure 1. New Horizons at Pluto [image: JHUAPL/SwRI].

After mentioning Rosetta in June, there is another deep space mission that I want to bring to your attention. The final preparations for the flyby of Pluto by the New Horizons spacecraft have started. New Horizons will be… read more


Submitted on 14 December 2014


Figure 1. Rosetta and Philae at comet [image: ESA–J. Huart].

There’s a truly cool deep space mission that I need to bring to your attention: Rosetta. Visit ESA’s Rosetta page for details. Rosetta is an ESA (European Space Agency) mission. It will be the first spacecraft that… read more


Submitted on 5 June 2014

Earth-Moon System Scale Model

Earth-Moon system scale model

It turns out that the balls in two popular sports, basketball and tennis, are almost exactly the right size for an Earth-Moon system scale model. Take a standard NBA basketball, which has a circumference of 29.5 in (74.9 cm). The diameter of the basketball is then 9.39 in (23.85 cm). If we let this ball represent the Earth… read more


Submitted on 20 April 2013

Earth-Moon System to Scale

Sun, Earth, and Moon, all to scale [Sun photo: Thomas Bresson]

The illustration shows the Earth-Moon system to scale, with the same scale used for size and distance. The diameter of the Earth is 12742 km, while the diameter of the Moon is 3475 km. So, to draw the Earth-Moon system to scale on a screen, each… read more


Submitted on 13 April 2013

The Spectacular Landing of Curiosity

Curiosity descent [image: NASA/JPL-Caltech]

Quite a while ago, I briefly reported on the spectacular Mars Science Laboratory mission that is currently under way. As you are probably aware, the Curiosity rover has now safely landed, and is already exploring the Red Planet. In this article, I want to tell you about the spectacular way in which the rover was put down on the surface. For previous Mars rovers like… read more


Submitted on 17 September 2012

Where to Launch Your Rocket?

If you want to launch a rocket into space, as I’m sure practically all of you are at least contemplating, where should you do that? The main thing is of course to avoid populated areas, to limit the damage if the thing blows up. The launch pad itself should be located away from people, and there should be a large uninhabited region to the east of the launch site… read more


Submitted on 10 April 2012

Mars Science Laboratory

Curiosity Mars Science Laboratory rover [image: NASA]

The Mars Science Laboratory (MSL) is one of the most spectacular planetary missions ever. The MSL homepage gives lots of details, and includes a countdown clock to the landing in… read more


Submitted on 7 February 2012