magnetic field – Page 3

Crashing comets may explain mysterious lunar swirls

3 June 2015 Astronomy Now

Lunar swirls have been the source of debate for years. The twisting, swirling streaks of bright soil stretch, in some cases, for thousands of miles across the Moon’s surface. Brown University researchers have produced new evidence that they were created by several comet collisions over the last 100 million years.

Blue aurorae in Mars’ sky visible to the naked eye

30 May 2015 Astronomy Now

For the first time, an international team of scientists from NASA, the Institute of Planetology and Astrophysics of Grenoble (IPAG), the European Space Agency and Aalto University in Finland, have predicted that colourful, glowing aurorae can be seen by the naked eye on a terrestrial planet other than Earth — Mars.

MESSENGER found evidence of Mercury’s ancient magnetic field

9 May 2015 Astronomy Now

About 4 billion years ago, Mercury’s magnetic field could have been much stronger than today, as indicated by low-altitude observations made by NASA’s MESSENGER spacecraft that revealed evidence of magnetisation of the innermost planet’s ancient crustal rocks.

Hubble views of Ganymede’s aurorae suggest a vast salty subsurface ocean

13 March 2015 Astronomy Now

Jupiter’s moon Ganymede is the largest moon in our Solar System and the only moon with its own magnetic field. NASA’s Hubble Space Telescope has the best evidence yet for a 60-mile deep underground saline ocean on Ganymede, believed to contain more water than all the water on Earth’s surface.