An Aurora Cupcake with a Milky Way Topping
Image Credit & Copyright: Göran Strand
Double auroral ovals above Östersund, Sweden.
Using a new, more accurate method for measuring the mass of galaxies that includes collecting information about the distances between the Milky Way, Andromeda and other close-by galaxies, an international group of researchers has shown that the Milky Way has half the Mass of the Andromeda Galaxy.
By studying both the galaxies in and immediately outside the Local Group, Walker was able to pinpoint the group’s center. The researchers then calculated the mass of both the ordinary, visible matter and the invisible dark matter throughout both galaxies based on each galaxy’s present location within the Local Group. Andromeda had twice as much mass as the Milky Way, and in both galaxies 90 percent of the mass was made up of dark matter.
The Milky Way as seen from Kazakhstan
photograph by: Elmar Akhmetov
M51, The Whirlpool Galaxy
Beautiful emission nebula NGC 6164 was created by a rare, hot, luminous O-type star, some 40 times as massive as the Sun. Seen at the center of the cosmic cloud, the star is a mere 3 to 4 million years old. In another three to four million years the massive star will end its life in a supernova explosion.
photograph by: Martin Pugh & Rick Stevenson
That’s crazy to think that something in the galaxy was forming at the same time as mammoths were lumbering about!
Hubble’s Jupiter and the Amazing Shrinking Great Red Spot
Gas giant Jupiter is the solar system’s largest world with about 320 times the mass of planet Earth. It’s also known for a giant swirling storm system, the Great Red Spot, featured in this sharp Hubble image from April 21. Nestled between Jupiter-girdling cloud bands, the Great Red Spot itself could still easily swallow Earth, but lately it has been shrinking. The most recent Hubble observations measure the spot to be about 10,250 miles (16,500 kilometers) across. That’s the smallest ever measured by Hubble and particularly dramatic when compared to 14,500 miles measured bythe Voyager 1 and 2 flybys in 1979, and historic telescopic observations from the 1800s indicating a width of about 25,500 miles on its long axis. Current indications are that the rate of shrinking is increasing for the long-lived Great Red Spot.