Using radar data collected by NASA’s Mars Reconnaissance Orbiter, researchers have found evidence of an ice age recorded in the polar deposits of Mars. Measurements show that about 87,000 cubic kilometres of ice have accumulated at the poles since the end of the last ice age about 370,000 years ago; the majority of the material accumulated at the Martian north pole.
The Sunspot Number, the longest scientific experiment still ongoing, is a crucial tool used to study the solar dynamo, space weather and climate change. It has now been recalibrated and shows a consistent history of solar activity over the past few centuries. The new record has no significant long-term upward trend in solar activity since 1700, suggesting that rising global temperatures since the industrial revolution cannot be attributed to increased solar activity.