Ever get the feeling the universe and Mother Nature are getting a little irritated at us?

Jupiter:

Something has smashed into Jupiter, leaving behind a black spot in the planet's atmosphere, scientists confirmed on Monday.

This is only the second time such an impact has been observed. The first was almost exactly 15 years ago, when more than 20 fragments of comet Shoemaker-Levy 9 collided with the gas giant.

"This has all the hallmarks of an impact event, very similar to Shoemaker-Levy 9," said Leigh Fletcher, an astronomer at NASA's Jet Propulsion Lab in Pasadena, California. "We're all extremely excited."

The impact was discovered by amateur astronomer Anthony Wesley in Murrumbateman, Australia at about 1330 GMT on Sunday. Wesley noticed a black spot in Jupiter's south polar region (see image) – but he very nearly stopped observing before he saw it.

Venus:

A strange spot emerged on Venus last week, and astronomers are not sure what caused it. They hope future observations will reveal whether volcanic activity, turbulence in the planet's atmosphere, or charged particles from the sun are to blame.

Amateur astronomer Frank Melillo of Holtsville, New York, first spotted the new feature, which is brighter than its surroundings at ultraviolet wavelengths, on the planet's southern hemisphere on 19 July.

Supervolcanoes:

Gary Egbert of Oregon State University in Corvallis, who is a magnetotellurics specialist but not a member of Hill's team, is cautious about the idea of a nascent supervolcano where Mount St Helens sits. "It seems likely that there's some partial melt down there," given that it is a volcanic area, he says. "But part of the conductivity is probably just water."

If the structure beneath the three volcanoes is indeed a vast bubble of partially molten rock, it would be comparable in size to the biggest magma chambers ever discovered, such as the one below Yellowstone National Park.

Every few hundred thousand years, such chambers can erupt as so-called supervolcanoes - the Yellowstone one did so about 640,000 years ago. These enormous eruptions can spew enough sunlight-blocking ash into the atmosphere to cool the climate by several degrees Celsius.

Could Mount St Helens erupt like this? "A really big, big eruption is possible if it is one of those big systems like Yellowstone," Hill says. "I don't think it will be tomorrow, but I couldn't try to predict when it would happen."

Looks like we'll have to go back to sacrificing goats and tipping them into the volcano's mouth....