The Crestone Eagle • May, 2021

Skies Over Crestone: May 2021

by Kim Malville

This is the month of Mercury and the moon.  Mercury will appear and the moon will become bloody in a total eclipse in the early morning of May 26.

Twisted magnetic fields of the black hole.

May 3: Just as the sky is darkening, some 45 minutes after sunset, look to the west to see Mercury, the most elusive of our naked eye planets. Beneath it you might spot Venus

May 12: Both Venus and Mercury will be easily visible soon after sunset. A tiny sliver of a crescent moon may be visible below Venus

May 13: The crescent moon will have moved next to Mercury.

May 15: There is another planet in the sky, Mars, and the moon will have moved next to it.

May 26: This is a special day for the moon.  It is a large, super full moon very bright and beautiful until it enters the earth shadow. The first clearly visible darkning will be around 3:44am in Crestone and it will be fully covered by our shadow by 5:18. The shadow of the earth contains all the sunsets and all the sunrises at that time.  Those rose-colored skies transfer their colors into the shadow producing sometimes a bloody red moon, which can be scary. It is really different from a total solar eclipse when suddenly an entirely different aspect appears in the form of the pearly white corona. For ancient cultures that worshipped the sun and viewed it as a god, an eclipse would have been an incredible revelation about a side of the sun they had not imagined.  A lunar eclipse, when the moon become covered with red, might reveal another dangerous feature of the moon god. 

Duration of eclipse: 3 hours, 3 minutes, 58 seconds

Duration of totality: 14 minutes, 28 seconds

Penumbral eclipse begins: 2:47:39am

Partial eclipse begins: 3:44:58am

Full eclipse begins: 5:11:26am

Maximum eclipse: 5:18:42am

Full eclipse ends: 5:25:54am

Moonset: 5:51:37am

May 28: Mercury comes within striking distance of Venus, about half of a degree at their closest. 

The shadow of a giant black hole

Jet from the black hole.

The galaxy known as M87 in the constellation of Virgo, at a distance of 55 million light years, contains one of the biggest black holes yet detected. Photographs of the shadow of the black hole were published two years ago showing its glowing sheath of hot gas, heated to incidence by the squeeze of the powerful gravitational field reaching out from the black hole.  We can’t see the black hole itself, only its shadow as it lies in front of the hot gas. It’s not like a planet that reflects light. The black hole absorbs light. If one used a search light to spot it, all the light would be sucked in. Fortunately for us, unlike Dracula, the black hole has a shadow. That shadow is immense, larger than our solar system and long enough to reach us 55 million light years away.  It is a strange and mind-boggling realization that we lie in the immense shadow of a black hole similar to the shadow of the earth that the moon will enter on May 26. 

This infographic details the locations of the participating telescopes of the Event Horizon Telescope (EHT) and the Global mm-VLBI Array (GMVA). Their goal is to image, for the very first time, the shadow of the event horizon of the supermassive black hole at the centre of the Milky Way, as well as to study the properties of the accretion and outflow around the Galactic Centre.

Some two years ago on 10 April, 2019, the Event Horizon Telescope team produced the first picture of the inner regions of a supermassive black hole, and even the skeptics could see for themselves that black holes really do exist. Then, less than two years later, on 10 March, 2021, a stunning new picture was released showing the curved magnetic fields in the gas surrounding the black hole. It is stunning because of the beautiful, finely combed magnetic field lines, associated with something so powerful, violent, and dangerous. It eats some 90 earths each day!  Everything about it is immense. Its spinning motion produces a powerful magnetic field that dominates the space around it. It contains the remains of over 2 billion stars. The glowing space around the dark shadow is several times the size of solar system.

Some is constantly falling inward, but some cannot reach the black hole because of these magnetic fields wrapped around it. It slides along those magnetic fields until it reaches the poles. Some goes in but other is flung out at speeds close to the speed of light in a jet of hot electrons and protons.

That jet appearing in the figure is 6000 light years long and contains hot electrons and protons   rocketing outward from M87’s black hole. Astronomers think such jets are the source of the highest-energy cosmic rays, particles that zoom through the universe at nearly the speed of light. 

These jets manage to transport energy released by the black hole out to the rest of the universe lake like a huge power cord. Some of that energy spewed out from the end of that 5000-light-year-long power cord has reached us as cosmic rays, having taken 55 million years to make the journey across space.


The Event Horizon Telescope that managed to capture this image links radio telescopes around the world to form a virtual telescope the size of Earth. There are now 11 telescopes, from the South Pole to a new one on the summit of the Greenland Ice Sheet.  The project gathers data only during a short window in the Northern Hemisphere spring each year, when the weather tends to be good at its various observing sites. We are hoping for more this spring.