Jupiter's Great Red Spot shrinks to smallest size ever
Thursday, May 15, 2014, 2:54 PM
Jupiter's Great Red Spot, an incredible storm that dwarfs even the most powerful hurricanes and typhoons here on Earth, has been a constant on the face of our solar system's largest planet for as long as astronomers have been peering at it through telescopes. However, although it has been there for hundreds of years so far, and it will likely last for at least hundreds more, it is not unchanging. In fact, the latest images from the Hubble Space Telescope show that it has shrunk to the smallest it's ever been seen.
When astronomers first got their close-up look at the Great Red Spot, it was a giant oval that stretched over 40,000 kilometres wide - large enough to fit three Earth's side by side by side, and still have room enough left over for Mercury to squeeze in as well. With subsequent observations over the years, from telescopes here on Earth, the nine different spacecraft that have flown by, and with observatories in space like the Hubble Space Telescope, the storm has been getting smaller. When the Voyager 1 and 2 spacecraft flew by, in 1979 and 1980, the Spot was only just over 23,000 kilometres wide. After the Hubble Space Telescope was launched, it began keeping track of the Spot as well, revealing how it continued to shrink, and more observations from the ground - including those from amateur astronomers - have shown that the rate of shrinkage is actually increasing.
The images below, the most recent full-disk view on the left, and close-ups of the Great Red Spot from 2014, 2009 and 1995, show how the storm has changed, not only getting smaller, but also becoming more circular.CLICK TO EXPAND:
"Recent Hubble Space Telescope observations confirm that the spot is now just under 16,500 kilometres across, the smallest diameter we've ever measured," said astrophysicist Dr. Amy Simon, from the Solar System Exploration Division of NASA's Goddard Space Flight Center, according to a press release.
The fact that the storm is shrinking doesn't mean that it will disappear. On the contrary, as the storm gets smaller, it's becoming more powerful, as the winds whipping around it increase in speed, fed by the smaller currents of air around it.
"In our new observations it is apparent that very small eddies are feeding into the storm," Simon added in the statement. "We hypothesised that these may be responsible for the accelerated change by altering the internal dynamics of the Great Red Spot."
Next week, on May 22nd, at 4 p.m. EDT, Dr. Simon will be joined by Tony Darnell and Carol Christian from the Space Telescope Science Institute (STScI) in a live video discussion to talk about these findings, and respond to any questions and comments from the audience. Tune in then!