Planetary nebula Menzel 3 (Mz 3), known as the Ant Nebula due to its resemblance to the small insect, is up to 8,000 light years from Earth in the Norma constellation. It should be noted that ‘planetary nebula’ is a misnomer; Mz 3 is actually the result of a dying star, but the ‘planetary’ moniker stuck for these sorts of structures after they were incorrectly classified by astronomer William Herschel in the late 18th Century.
This bizarre nebula’s similarities to an ant can be seen in the accompanying image. The ‘head’ is on the left, the ‘thorax’ is to the right and the ‘legs’ are the emissions streaming out from the nebula. From its ‘head’ to the end of the ‘thorax’ the Ant nebula spans an entire light year across. At the centre of the nebula is a star in the last throes of its life that is ejecting material into the surrounding space.
In such an instance, it would be expected that the material would be flung in a spherical manner, but the cause of the odd symmetrical shape of the Ant nebula is puzzling. The predominant theory is that the dying star is in a binary system with a companion at a distance comparable to that of the Earth and Sun, with the other star sweeping the material into the ‘ant’ shape. Another theory suggests that the strong magnetic fields of the dying star are directing electrically charged gas moving at 1,000 kilometres (600 miles) per second along the magnetic field lines to produce the ‘ant’.
The Ant nebula’s central star is thought to be very similar to our own Sun and, because of this, astronomers are hopeful that by understanding what exactly is going on at the heart of Menzel 3 they may be able to predict what will become of the Sun, and indeed the Earth, in the distant future several billion years from now.