Chelsea Whyte, contributor
For a four-billion-year-old volcano, Tharsis Tholus isn't looking half bad. This extinct Martian crag would dwarf most mountains on Earth and, though it's looking a little worse for wear due to the erosion and collapses that have occurred over the aeons, it's still standing tall.
This image of the giant peak was released yesterday by the European Space Agency. It is a composite of multiple photos taken by a high-resolution stereo camera aboard the Mars Express spacecraft in 2004, with different elevations shown in different colours.
The volcano looms 8 kilometres above the surrounding landscape - almost the height of Earth's tallest peak, mount Everest. Yet, compared to other Martian volcanoes, Tharsis Tholus is still pretty average in terms of height.
Pascal Lee, co-founder of the Mars institute and principal investigator on NASA's Haughton-Mars Project, explains: "Because the gravity on Mars is only 38 per cent what it is on Earth, it can have mountains three times taller than on Earth."
The thing that really makes Tharsis Tholus stand out among the other Marsian giants is its battered condition. It long ago spent its lava, leaving a gaping cavity in the centre, which is coloured here in green. The lack of support for the roof caused the walls to collapse, resulting in the leftover ridge, shown in brown in the picture.
dan wheldon walking dead weldon weldon danica patrick david garrard indy car
Tidak ada komentar:
Posting Komentar