Feb 12

What’s Up in the Sky

What’s Up in the Sky – February, 2019

Ultima Thule – A Blast From the Past

Late last year, an object with a very interesting name was in the news. That was Ultima Thule, the latest discovery made by the New Horizons spacecraft. Go to https://apod.nasa.gov/apod/astropix.html, click on “Archive” and look at the photo from January 29.

At that time not much was known about this object other than it had a weird name. In order to find out what we have discovered so far I turned to a reliable source, Dr. Harold Reitsema, a project scientist on NASA missions who worked on New Horizons. Dr. Reitsema is also a member of the Shoreline Amateur Astronomical Association, and Holland resident and agreed to an interview for this story.

“Thule” refers to the edge of the known world, and is a term that has been around for about a thousand years. “Ultima” simply reinforces that idea and is appropriate because it is the most distant object in the solar system to be visited by a spacecraft and that is where New Horizons is. It is an informal name chosen from a list of submissions to an internet poll. Currently, the real name is 2014 MU69 (which is kind of “nerdy” in Dr. Reitsema’s view) but even that is only temporary until the International Astronomical Union assigns a permanent name that follows current protocol.

Ultima Thule resides in the Kuiper belt, a region of the solar system that extends about 10 AUs beyond Pluto (an AU, or astronomical unit, is the average distance from the Earth to the Sun) and contains over a million asteroid-like objects ten kilometers or larger in diameter. It was discovered in 2014, eight years after New Horizons was launched. It took a massive effort by New Horizons team members using the Hubble Space Telescope, to pinpoint its location.

Based on these observations, New Horizons was able to make small corrections in its trajectory that allowed it to pass a little over three thousand kilometers (slightly less than two thousand miles) of its target. That’s like sinking a three pointer from over two hundred eighty miles.

So why Ultima Thule? What could we possibly learn from a tiny object so far away? Dr. Reitsema explained that the very early stages of the formation of the solar system are difficult to study due to a lack of data from samples dating back 4.5 billion years. Planets, their moons, and asteroids have all undergone changes since the solar system first formed. The craters on the Moon are an example. Even Pluto suffered a great collision that formed its moon, Charon. Dr. Reitsema explained that we wanted to “look at a very pristine thing that looks like it did when it formed”. So this object, undisturbed since its formation, is going to look like what “small things that got together and made bigger planets looked like originally”.

There is still more to learn about Ultima Thule and much evidence is forthcoming from pictures that have yet to be downloaded from the spacecraft. At the time of my interview, there was very little evidence of impact craters on its surface, but as you can see from the picture mentioned above, we continue to learn much each week as additional images arrive. That picture alone explains why people like Dr. Reitsema devote their careers to studying what’s up in the sky.

This month in history:
Feb. 1: Shuttle Columbia breaks apart during reentry killing all 7 astronauts – 2003
Feb. 7: First untethered spacewalk made by Bruce McCandless – 1984
Feb. 14: Voyager 1 looks back to take photo of solar system – 1990
Feb. 18: Pluto discovered – 1930
Feb. 20: John Glenn is first American to orbit Earth – 1962
Feb. 28: Charles Bassett and Elliot See, Gemini IX crew, die in plane crash – 1966

Dec 31

What’s Up in the Sky

What’s Up in the Sky – January, 2019

January Features the Moon and Planets

Whether you’re a late night person or an early bird, January has something for everyone.

You may recall last January 31st when there was a rare (the last one was in 1866) Super Blue Blood Moon, when the Moon is not only closest to Earth in its orbit (“Super”) and is the second full Moon of the month (“Blue”), but it is also totally eclipsed (“Blood”). Unfortunately, this rare event was not visible from West Michigan, but on January 20-21 this year, we will be in position to witness, weather permitting, a Super Blood Moon, just like last year, but without the “Blue” part.

The lunar eclipse begins around 10:30 p.m. with totality beginning about an hour later. The Moon will be deepest in Earth’s shadow at 12:12 a.m. During totality, see if you can spot the bright stars Castor, Pollux, and Procyon nearby. It’s also fun to imagine how the scene would appear to an astronaut on the Moon looking back at Earth. She or he would see the disc of Earth surrounded by a thin ring of red light from all the sunrises and sunsets happening on Earth at that moment. During totality, the Moon’s surface is lit only by this ring, thus the reddish hue of the Moon at that time. So mark your calendar for the night of January 20/21 to see this beautiful event.

Another celestial show will also occur this month, this one involving not only the Moon but also several bright planets. The only downside is that you will have to be out before sunrise to see it, but this time of year that’s during the morning commute.

You probably won’t be into looking at the predawn sky on New Year’s Day so rest assured that you won’t miss much if you wait until January 2nd. Looking southeastward around 7:30 a.m. you will see brilliant Venus just above a crescent Moon with slightly fainter Jupiter to the pair’s lower left. If by some miracle it is clear the following morning look for an even thinner crescent Moon just to the left of Jupiter.

Keep observing as often as possible to see the two bright planets move past each other as the month progresses with the minimum separation occurring on January 22. The show repeats at the end of the month and culminates with an even closer pairing, this time between the Moon and Jupiter on January 31.

With interesting sights all month, you can take advantage of any clear days to enjoy what’s up in the sky.

This month in history:
Jan. 1: Asteroid Ceres discovered by Giuseppe Piazzi-1801
Jan. 4: NASA cancels further production of Saturn V rockets-1970
Jan. 13: Galileo discovers Ganymede, moon of Jupiter-1610
Jan. 19: New Horizons spacecraft launched on it’s journey to Pluto-2006
Jan. 27: Apollo 1 astronauts Chaffee, White and Grissom die in fire in capsule-1967
Jan. 28: Seven astronauts killed when Space Shuttle Challenger explodes during launch-1986

Dec 02

What’s Up in the Sky

What’s Up in the Sky – December, 2018

Bright Stars Make Their Way Into December’s Sky

I was recently in a local Meijer store admiring a very nice seasonal display depicting a winter nighttime scene complete with snowy hills and pine trees, a horse-drawn sleigh, reindeer, and a dark, starry sky. But what really got my attention was the comet in the sky. It was a big comet, spanning a good portion of the sky, and, to the artist’s credit, it was a pretty good rendition of a comet -closely resembling 1998’s comet Hale-Bopp.

It reminded me that the sky is full of beacons and spotlights, patterns and stories, many of which have religious connections, with the Star of Bethlehem and the crescent Moon being two examples. I have written before about the traditions of the season and their relationships to celestial objects and events, but this year I would like to focus on the stars and constellations that are visible and offer some lesser-known facts and tidbits about them.

Many readers are familiar with the Summer Triangle which consists of the stars Vega, Deneb, and Altair, which are in the constellations Lyra, Cygnus, and Aquila, respectively. By now, however, these constellations are no longer high overhead, but are now setting in the west as the evenings get darker. Look for the Northern Cross, standing upright near the western horizon an hour or so after sunset.

In the opposite direction are the constellations of winter that will dominate the southern sky in the coming months. These include Orion, Canis Major and Minor, Gemini, Auriga, and Taurus, which contain the bright stars Rigel, Sirius, Procyon, Pollux, Capella, and Aldebaran, respectively. The group is often referred to as the Winter Hexagon. One interesting feature of this group of stars is that, other than Rigel, they are all 65 or fewer light-years away. In fact, going clockwise from Sirius, the distances are 8 light-years, 11 ly (Procyon), 34 ly (Pollux), 42 ly (Capella), and 65 ly (Aldebaran).

Turning your attention straight up you will also find much to enjoy. Almost directly overhead lies the constellation Andromeda, home of M31, the Andromeda galaxy. The constellation Andromeda is not very prominent so I usually use other constellations as guideposts. One side of the “W” shaped Cassiopeia can be viewed as an arrow pointing at the constellation, for example. Consult any sky or star chart for a more detailed description. Or just set up a warm sleeping bag and scan overhead with binoculars. You will know when you have found M31. If you are under dark skies, in fact, it can be seen with the naked eye. It is the only naked eye object in our sky that is not a member of our own Milky Way galaxy. The stars in our galaxy make up everything else up in the sky.

This month in history:
Dec. 3: Pioneer 10 spacecraft makes closest approach to Jupiter – 1973
Dec. 11: First auction of Soviet space hardware and artifacts – 1993
Dec. 14: Gene Cernan, Apollo 17 astronaut, is last human to walk on Moon – 1972
Dec. 20: Founding of Mt. Wilson Solar Observatory – 1904
Dec. 24: Apollo 8 astronauts give us inspirational moment from lunar orbit – 1968
Dec. 25: Isaac Newton born – 1642

Nov 19

What’s Up in the Sky

What’s Up in the Sky – November, 2018

Getting a Closer Look at Mercury

Of all the planets, it is not surprising that the one that has been visited and studied by spacecraft from Earth the most often is Mars. It is nearby and relatively easy to get to although it is also very difficult to land on. Its surface gravity is similar to Earth’s and its surface conditions are cold and dry, but manageable, just like in the movie, The Martian. There are currently a number of spacecraft both on the surface and in orbit studying all sorts of things about Mars, most of which are related to a search for water.

It may surprise you, however, that the planet Mercury is one of the planets visited by the fewest spacecraft – two. In 1974 and 1975, Mariner 10 flew past Mercury three times and mapped almost half the planet’s surface. In 2011, Messenger went into orbit around the planet and completed mapping 100 percent of its surface. However, its data forced astronomers to rethink their theories of how the planet formed, its geography, and its surface features.

A third mission to Mercury was launched on October 19 and is currently on its seven year journey to the planet. Named BepiColumbo, the mission is a joint venture by the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA) and includes a carrier spacecraft and two orbiters. It is named after Giuseppe “Bepi” Columbo who was an Italian mathematician and engineer in the mid twentieth century who discovered important features of Mercury’s orbit.

The spacecraft is composed of the Mercury Transfer Module (MTM), which provides electrical power during the journey from Earth, and two orbiters, ESA’s Mercury Planet Orbiter (MPO) and JAXA’s Mercury Magnetospheric Orbiter (MMO). The orbiters will separate from the MTM just before the spacecraft reaches orbit around Mercury. They will then be put in separate orbits and begin collecting scientific data.

Scientists hope the mission will help them understand not only how the planet had formed but also provide important information about the solar system’s formation. Some of the mission’s objectives include: study the planet’s geology, interior structure, composition and craters; determine the origin of Mercury’s magnetic field; investigate polar deposits; and perform a test of Einstein’s theory of general relativity.

BepiColumbo will also be the first ESA interplanetary mission to use solar-electric propulsion. Used successfully by a number of NASA and JAXA missions in the past, the system uses electricity generated by the spacecraft’s solar panels to create xenon ions that are accelerated to extreme speeds by powerful magnetic fields. The ion stream is of low mass but high velocity and must deliver thrust over a long period of time.

Along with the new generation of giant telescopes and upcoming missions to planets and asteroids, projects such as BepiColumbo will continue to give us a better understanding of what’s up in the sky.

This month in history:
Nov. 9: Carl Sagan born. – 1934
Nov. 12: Great Leonid Meteor Shower – 1833
Nov. 16: Interstellar message broadcast from Arecibo radio telescope – 1974
Nov. 19: Second lunar landing made by Apollo 12 – 1969
Nov. 27: First photograph of a meteor shower – 1885
Nov. 30: Fragment of 10-pound meteorite strikes and bruises Alabama woman, Elizabeth Hodges-1954

Jul 02

What’s Up in the Sky

What’s Up in the Sky – July, 2018

Harmony Has Long Been Sought in the Sky

If you are out in the country, the sounds of summer have replaced the silence of winter in the starry skies. Night birds, cicadas, and crickets accompany the “music of the spheres”, which refers to the ancient belief that the stars in their motions made music of a most wonderful harmony. Pythagoras even believed that all existence is governed by the laws of musical harmony. The Greek concept of the “music of the spheres” even influenced the great Renaissance astronomer Johannes Kepler who attempted to explain Copernican planetary motions by using the laws of music. He did not achieve his goal, but on the way he discovered his famous laws of planetary motion.

I sometimes lament the fact that the sun sets so late at this time of year (just before 9:30 p.m. tonight), that it’s difficult to do any serious observing without staying out well past midnight. Although there is truth in that statement, there is also a flip side. The weather should be more cooperative and there will be great things to see even early in the evening. And as the month progresses, the Sun sets earlier so the nights will begin twenty minutes sooner by the end of the month.

July will offer quite the variety of things to observe this year. Let’s start with planets. You’ve probably been watching Venus, the bright evening star that has dominated the western sky at dusk the past couple of months. On the fifteenth of this month she will be joined by a beautiful, thin crescent Moon, so close together that you won’t be able to fit two fingers held at arm’s length between them. This will be the best pairing of the two that I have seen in many years. Look west any time after sunset. In fact, you could use binoculars to see how early you are able to spot the planet.

Venus isn’t the only visible planet this month. Look right below the Moon on the fourteenth for Mercury (use binoculars). Look due south to see Jupiter about a third of the way up from the horizon and brighter than everything except Venus. Farther in the southeast lies Saturn, shining brightly over the constellation Sagittarius, the Teapot. Later Mars will rise in the southeast and begin its summer show when it is at opposition (in the opposite direction as the Sun) on July 26. Being at opposition, the telescopic viewing of the planet will be at its best.

The summer constellations begin to take their places in the sky with promises of sights to come. Look overhead for the Big Dipper and Bootes and further east for the summer triangle. Meanwhile, the southern horizon promises to reveal Scorpio and Sagittarius while Hercules, with its magnificent star cluster, is nearly overhead. In the next few months there will be plenty to see up in the sky. 

This month in history:

July 1: 100 inch mirror arrives at Mt. Wilson Observatory – 1917
July 4: Supernova, whose remnant is known as the Crab Nebula, is witnessed – 1054
July 4: Mars Pathfinder lands on Mars – 1997
July 6: Newton’s book, Principia, is published – 1687
July 9: Voyager 2 flies past Jupiter – 1979
July 20: Humans walk on Moon for the first time – 1969
July 24: First rocket launched from Cape Canaveral – 1950

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