An M80 with No Kaboom

M80This one’s a star cluster not a firecracker.

M80 is in the constellation Scorpius between the stars α Scorpii (Antares) and β Scorpii in a part of the Milky Way rich in nebulae. When viewed with a modest amateur telescope (like mine), it appears as a mottled ball of light. This Hubble image shows more detail. M80 is roughly 95 light-years in diameter. It contains several hundred thousand stars, making it one of the more densely populated globular clusters in the galaxy.

M80 contains a fair number of blue stragglers, stars that appear to be much younger than the cluster itself. Astronomers believe that these stars lost part of their outer layers during close encounters with other cluster members or as the result of collisions between stars in the tightly packed cluster. Images from Hubble show regions with very high blue straggler densities which suggests that the center of the cluster probably has a very high capture and collision rate.

Image Credit: NASA

A Helicopter on Mars

Nighttime temperatures at Jezero Crater on Mars can drop to -90 C which can damage unprotected electrical components and ruin batteries. However, the Ingenuity helicopter survived its first night after being deployed from the Perseverance rover on 3 April. If all goes well, Ingenuity will be the first aircraft to attempt powered, controlled flight on another planet.

Image Credit: NASA

The Veil Nebula

The Veil Nebula is about 2,100 light-years from Earth in the constellation of Cygnus (the Swan), making it a relatively close neighbor in astronomical terms. It’s the visible portion of a supernova remnant formed around 10,000 years ago known as the Cygnus Loop.

This image which only shows a portion of the nebula. It was assembled from data taken using five different filters with the Wide Field Camera 3 on the Hubble Space Telescope. Post-processing of the data brings out enhanced details of emissions from doubly ionized oxygen (blues) and ionized hydrogen and ionized nitrogen (reds).

Image Credit: NASA / ESA / Z. Levay

Just Passing By—For Now

Asteroid 99942 Apophis made a relatively distant pass by Earth on 5 March. It will be back. This animation shows the trajectory of  the asteroid as it flies safely past Earth on 13 April, 2029. Earth’s gravity will slightly deflect the trajectory as the 340-meter-wide Near-Earth Object comes within 32,000 kilometers of the Earth’s surface. The motion has been sped up by a factor of 2,000. Recent observations and refined calculations show that 99942 Apophis should not hit the Earth for at least a century.

Video Credit: NASA / JPL

Supernova Leftovers

About 11,000 years ago, a star went supernova. The light from this event first reached Earth around A.D. 1667. There are no records of anyone noticing probably because large amounts of dust between the dying star and Earth obscured our view of the explosion.

The remnants of this supernova was finally noticed in 1947 by radio astronomers. Now known as Cassiopeia A, it is one of the brightest radio sources in the whole sky. More recently, the Wide-field Infrared Survey Explorer (WISE) was used to observe the infrared echoes from the supernova.

When WISE took this image, the blast wave had expanded out to about a distance of 21 light-years, but he flash of light from the explosion, traveling at the speed of light, had covered well over 300 light-years. The orange-colored echoes further out from the central remnant have been reflected from interstellar dust that was heated by the supernova flash centuries after the original explosion.

Image Credit: NASA / JPL / UCLA

Quote of the Day

Thermodynamics is a funny subject. The first time you go through it, you don’t understand it at all. The second time you go through it, you think you understand it, except for one or two small points. The third time you go through it, you know you don’t understand it, but by that time you are so used to it, it doesn’t bother you any more.

—Arnold Sommerfeld

And Now For Something Completely Different

Mars is a much more hospitable neighbor than Venus, so we’ve sent a lot more mission there. Pictures taken by rovers on the planet’s surface are not uncommon these days. Gentle Reader, when was the last time you saw a picture taken on the surface of Venus?This was taken by Venera 14, a robotic Soviet lander which parachuted and air-braked down through the thick Venusian atmosphere in March, 1982. The desolate landscape it saw included flat rocks, vast empty terrain, and a featureless sky above the landing site near Venus’ equator. The climate on Venus is very inhospitable with temperatures hot enough to melt lead (near 450 C) and pressures 75 times that on Earth. The instruments on Venera 14 lasted only about an hour.

Image Credit: Soviet Planetary Exploration Program

Coming Together and Coming Apart

Whirlpool in radioThis composite image of the Whirlpool Galaxy and it’s nearby companion galaxy overlays radio astronomy data from the Very Large Array with optical data.  The image in white shows how the galaxies appear to optical telescopes: one giant spiral galaxy with a smaller one hanging off an arm. The VLA sees a much bigger picture. The blue overlay reveals the the cast-off gases that were once in the outer spiral arms of these galaxies which have been pulled apart as the smaller galaxy has moved passed the larger one.

Image Credit: NRAO

Black Holes and Star Formation

The supermassive black holes lurking at the centers of galaxies draw from the disks of gas and dust that orbit them. Massive jets of matter result that affect star formation locally and farther afield. This animation shows a model of that interaction. Watch as the jets and winds from a supermassive black hole affect its host galaxy and the space hundreds of thousands of light-years away over millions of years.

Video Credit: STScI