What’s Up in the Sky – April, 2020

A Great Month Ahead

I am excited about the coming month. Not only will there be some very nice observing opportunities and historic events to remember, but an event of great personal significance will occur, one which I plan to observe.

April will start off with a real bang, easily visible in the western sky after sunset. I am sure most readers have noticed the planet Venus shining like a beacon out over the lake after sunset. Next week observers will be treated to a spectacular display of orbital mechanics as Venus appears to pass through the Pleiades star cluster. Although it will be visible to the naked eye, binoculars will give you a better view of the planet passing close to individual stars in the cluster. A telescope aimed at the scene will allow you to witness the movement of the planet against the background star cluster. It promises to be a rare and beautiful sight!

Conjunctions of Venus and the Pleiades occur every year at this time, but rarely does the planet appear to pass through the cluster. However, every eight years nearly to the day, the planet crashes the party and becomes the brightest member of the group.

You can begin observing this event right away by watching each night as the planet inches closer and closer to the cluster. On April 3, Venus will be with the seven sisters for their eight year reunion. Don’t miss it. Even if the weather does not cooperate, don’t give up. This reunion will be visible all week and even one sighting will be worth it.

The following week the Moon may be seen passing close to the planets Jupiter, Saturn, and Mars. Unfortunately, you have to be up before sunrise to witness this event, easily visible low in the southeast.

Between these events, on April 7, will be a Supermoon – a full moon that occurs when the Moon is at the point in its orbit where it is closest to Earth, causing it to appear larger than usual. Although this phenomenon gets a lot of press, you really won’t notice it being any larger than usual unless you could view a side by side comparison with October’s full Moon.

At the end of this column you can see that April is an historic month for space exploration. I have always found it interesting that the first person in space and the first Shuttle launch occurred exactly twenty years apart and you can also see that this is the thirty year anniversary of the Hubble Space Telescope’s launch. But this month marks forty one years since one of my first, and greatest, astronomical observations.

You may have noticed the Moon, Venus, and the Pleiades forming a lovely triangle last night. On Saturday, April 25, the Moon will also have a close encounter with the bright star Aldebaran. A similar event occurred on Saturday, April 28, 1979, only that time, the Moon actually occulted (passed in front of) Aldebaran, blocking the star from view.

On that date, my wife and I were driving to Kalamazoo for a gathering of friends. It was a clear evening so, as Lyne drove, I watched Aldebaran approach the Moon’s unlit edge. I knew the occultation would happen soon, so when we arrived I told everyone to come outside and see it. Only one other person joined me.

It was the end of twilight with a crescent Moon. We both thought we would see the star fade out and disappear but instead, BAM! it was gone! Both of us were not only amazed at what a tremendous sight it was but also astonished that we were the only witnesses. When we tried to share our amazement with the others we got comments like, “. . . what’s the big deal, doesn’t that happen every night?”

Actually, no, it doesn’t. It may seem like the Moon should pass by many stars on its nightly journey through the sky, but actually, the stars are basically moving with it and most are not in its path. So occultations such as that one are extremely rare and when you consider timing, weather, and conflicting activities, it turns out to be one of the rarest of sights one can witness up in the sky.

This month in history:
April 01: Comet Hale-Bopp nearest Sun – 1997
April 02: First photograph of Sun taken – 1845
April 12: Yuri Gagarin becomes first human in space – 1961
April 12: Columbia is first space shuttle to be launched – 1981
April 17: Apollo 13 returns to Earth – 1970
April 25: Deployment of Hubble Space Telescope – 1990
April 28: Eugene Shoemaker is born – 1928

What’s Up in the Sky – March, 2020

How NASA Missions Are Born

Voyager, Pioneer, the Curiosity Rover, the Hubble Telescope and the New Horizons space craft all have one thing in common – they were all conceived, built, and delivered to NASA by its contractors. But not all missions are alike in these ways, and not all proposed missions even make it to the drawing board. Let’s take a look at the process of getting an idea into space.

I talked with Dr. Harold Reitsema, a member of the Shoreline Amateur Astronomical Association and semi-retired rocket scientist who worked on both the Kepler and New Horizons spacecraft. He explained that NASA “does science missions in two very different ways”.

The first is known as a “Principal Investigator Led Mission” in which a team of knowledgeable scientists is formed, then becomes aligned with a spacecraft builder, some NASA scientists and even sometimes a NASA center, and finally puts together a complete mission design. The design includes the satellite, its instruments, who the operator will be, and how the data that comes from the spacecraft is stored and analyzed. The team then writes a proposal that was solicited by NASA through what is known as an “Announcement of Opportunity”.

This announcement defines a broad area of science, such as cosmology or the origin of the solar system, and anyone with an idea that fits that objective can respond with a proposal for a full mission. Proposals can therefore be quite diverse. For example, one might be for an orbiter to study the atmosphere of Jupiter while another proposes a lander on Venus. Both fall under the category of planetary exploration.

NASA then creates two panels, one that evaluates the value of the science and one that studies the risks associated with building the hardware to actually accomplish the mission’s goals. The scientists submitting the proposals then approach private industries such as Lockheed or Ball Aerospace to work out the design and construction details. Often industries try to work with proposals from several teams to increase the chances of being approved since each Announcement of Opportunity can be met with a dozen or more proposals. The Kepler telescope and the New Horizons spacecraft were both missions of this type that Dr. Reitsema worked on for Ball Aerospace. Clearly, those proposals were accepted.

Such missions are relatively low in cost and risk. Larger, more expensive endeavors, such as the Mars Rovers or the Hubble Telescope, take a different course from conception to completion. In these cases, NASA puts out a list of requirements that a mission must meet and requests proposals from the aerospace industry that meet these requirements. The James Webb Telescope is a prime example. NASA knew they wanted to do a really big infrared telescope and it needed to be able to aim with a high accuracy, have a particular sensitivity, size, and life expectancy, and operate at extremely low temperatures. NASA then puts out a Request for Proposals to accomplish their mission.

Such endeavors require vast resources so the number of proposals is limited and they almost always come from the aerospace industry. Since these missions have never been done before and often require untested or even nonexistent technologies, NASA is willing to cover certain cost overruns. Again, the Webb is a good example. Originally proposed at a cost of around $1.6 billion in 1997, it jumped to $5 billion by 2007 and now is estimated at almost $9 billion! Part of the problem was that it is very difficult to perform tests here on Earth to evaluate how it will behave in a weightless environment, with its optics near absolute zero and electronics at room temperature.

So, to summarize, missions are the result of two processes. In the first, groups propose different ideas in response to an announcement of opportunity from NASA to study a broad branch of science. In the second, proposals are submitted for specific investigations as defined by NASA. Each scenario brings us a better understanding of what’s up in the sky.

This month in history:
March 01: George O. Abell born – 1927
March 08: Voyager 1 project scientist, Linda Morabito, discovers first active extraterrestrial volcanoes (on Jupiter’s moon Io) – 1979
March 14: Albert Einstein born – 1879; Gene Cernan born – 1934
March 18: Soviet rocket explosion at launch pad kills 50 workers – 1980
March 22: Comet Hale-Bopp passes closest to Earth – 1997
March 31: Saturn’s largest moon, Titan, discovered by Dutch astronomer Christiaan Huygens – 1655

What’s Up in the Sky – February, 2020

It’s Venus

If you venture out any time after sunset and look to the southwest, you will be sure to spot a very bright light high over the horizon. Several friends have asked me about it so I thought I would satisfy everyone’s curiosity and confirm your suspicions by telling you that it is indeed the planet Venus. Last week Venus appeared very close to the crescent Moon, a close encounter that will repeat itself this month. On February 27, the two will again form a beautiful, close pair in the western sky for several hours after sunset.

Venus has played quite an important role in human history. In the ancient tradition of attributing that which is unexplained to the “gods”, Venus was named after the goddess of love and beauty. All the planets had special significance to early civilizations because they did not follow the normal behavior of everything else in the sky, Sun and Moon notwithstanding. The visible planets demonstrated god-like behavior, being seen in different locations at different times of year. Being one of the brightest objects in the sky, Venus has been revered by civilizations throughout recorded history.

Mercury and Venus both will be visible this month low in the west after sunset. On Monday, February 10th, look about 40 minutes after sunset. Mercury will be about two fist-widths down and a little to the right of Venus. You will probably need binoculars to see Mercury.

Besides her historical significance, Venus has played an important role in the history of science. It was the first planet to have its positions plotted in the sky, almost four thousand years ago. In the middle ages, Galileo’s observations of the phases of Venus offered evidence of a Sun-centered, not Earth-centered system.

Due to its close approaches to Earth, it was an early target for planetary exploration. When Mariner 2 made its close flyby in 1962, it marked the first time any planet had been visited by a spacecraft. Venus also became the first planet to have a spacecraft from Earth land on its surface when Venera7 did so in 1970.

Venus is the planet with the highest surface temperature (over 850 degrees F) not because of its close proximity to the Sun, but because of global warming. Its atmosphere is about 98% carbon dioxide which traps most the heat from the Sun and creates a runaway warming cycle.

Transits of Venus, when the planet travels directly between the Sun and Earth and appears as a black dot moving across the face of the Sun, are relatively rare events. The last one occurred in 2012 but the next one won’t be until 2117. There is some historical significance to this event. In 1768 Captain Cook sailed to Tahiti to observe a transit of Venus.

Not all the action takes place in the evening this month. I know pre-dawn observing can be a challenge in the workaday world, but on Tuesday, February 18, the crescent Moon will occult (pass in front of and block out) Mars. This will occur at 7:10 am so grab a pair of binocs and start watching around 7. Look every few minutes as their separation until Mars disappears behind the Moon.

I have seen a few occultations and can assure you that you will think it is one of the coolest things you’ve ever witnessed up in the sky.

This month in history:
Feb 01: Shuttle Columbia breaks apart during reentry killing all 7 astronauts – 2003
Feb 06: Alan Shepard hits first golf balls on the Moon – 1971
Feb 15: Galileo Galilei born – 1564
Feb 18: Pluto discovered – 1930
Feb 20: John Glenn is first American to orbit Earth – 1962
Feb 24: Detection of first pulsar (by Jocelyn Bell in 1967) is announced – 1968

What’s Up in the Sky – January, 2020

Important Work Being Done by Spacecraft

Lately I have found myself writing about things most readers will never see, mostly due to the weather, but timing, observing site availability and other commitments all affect our observing experience.

So my topic to kick off the new decade is a tale of two spacecraft – the Spitzer Space Telescope and the Parker Solar Probe. The former is near the end of its mission, the latter is just getting started.

First known as the Shuttle Infrared Telescope Facility (SIRTF), the Spitzer was born when NASA was seeking payloads for the Space Shuttle program. The telescope was one of four “Great Observatories” launched by NASA in the 90s and early 2000s that studied the universe in four different wavelengths of electromagnetic radiation. Spitzer observed infrared radiation, the Hubble Space Telescopes captures visible light, the Chandra X-ray and Compton Gamma Ray observatories’ names speak for themselves.

With the Spitzer Space Telescope we can not only look back in time but also observe invisible objects. Because of the expansion of the universe, light from distant galaxies is stretched to longer wavelengths (infrared) and that radiation took as many as ten billion years to reach us. So Spitzer is seeing things as they were ten billion years ago. Also, infrared radiation can penetrate our galaxy’s giant molecular clouds to enabling Spitzer to used to study stellar evolution.

But it’s the study of exoplanets in which Spitzer excels. Many exoplanets lie in orbits seen edge on alternately passing in front of and behind their star. The tiny dips in brightness as the planet passes directly in front of the star can be measured precisely by Spitzer. Some of the most important observations of distant planetary systems have been made in this manner.

After a remarkable 16-year exploration of the infrared universe, Spitzer will be retired on January 30.

The flip side of that coin is the Parker Solar Probe, a spacecraft currently in an orbit around the Sun that stretches out to Venus. With the primary goal of studying the Sun’s corona and solar wind, the spacecraft will dip as close as 4 million miles from the “surface”. This will enable it to study the speed of the solar wind and the birthplace of the highest-energy solar particles.

Parker Solar Probe will make 24 orbits of the Sun including 7 close encounters with Venus for “gravity assists”. The entire mission will last almost seven years. The mission is critical in that it will increase our understanding of the interaction between the solar wind and the Sun’s corona. This, hopefully, will lead to a clearer picture of the causes of the coronal mass ejections or “solar storms” that can disrupt electronics and power transmission.

So, although not objects for astronomical observations, these satellites are just two of the spacecraft doing important work up in the sky.

This month in history:
Jan. 1: Isaac Azimov born – 1920
Jan. 4: NASA cancels further production of Saturn V rockets – 1970
Jan. 13: First women astronauts selected by NASA – 1978
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

What’s Up in the Sky – December, 2019

A Look Back at History and Up at the Planets

Nineteen sixty eight was both a very bad and a very good year. The Smithsonian Magazine devoted an entire issue to 1968 as several historical events occurred that year, not all of them very uplifting, to say the least. There were assassinations (Martin Luther King, Jr., Robert Kennedy), riots (the Democratic convention in Chicago), and numerous protests against the war in Viet Nam. But the year ended on a high note when the Apollo 8 astronauts, Frank Borman, Bill Anders, and Jim Lovell, made the first manned trip to the Moon, orbiting it ten times before returning to Earth.

The crew made history in a couple of other ways as well. You are probably familiar with the famous “Earthrise” photo of our own planet suspended in a vast black sky over the lunar horizon. But probably the most memorable event of the mission occurred when the three astronauts each read several verses from the Book of Genesis in a live television broadcast on Christmas Eve. Finally people could enjoy an uplifting story of bravery and courage, of exploration and discovery, and a positive ending to an otherwise negative year. In fact, after the mission, Borman received a telegram that said, “Thank you Apollo 8. You saved 1968”.

Although this month might not turn out to be quite as historic as 1968, there will still be some interesting sights to enjoy, starting with tonight. Look low near the southwest horizon at 6:00 p.m. and you should be able to spot three planets and the crescent Moon in a straight line. Given the necessary conditions of a clear sky and a view of the horizon, they should be easy to spot as they are the brightest objects in the sky at the time. Venus will outshine them all with Jupiter close behind to her lower left. Above and to the right of Venus look for faint Saturn near the handle of the Teapot in Sagittarius.

Although Jupiter will quickly fade away toward the horizon, the other two will remain visible and will get closer and closer together as Venus moves past Saturn over the next few days. They will appear closest on Tuesday and Wednesday, December 10 and 11 when their separation will be about the size of four full Moons.

But that’s not all. Stay with Venus all month and you will be rewarded with a spectacular view of the planet shining brightly over a thin, crescent Moon on Saturday, December 28.

The month of December is a time when there really aren’t that many notable constellations well placed for viewing. The summer triangle is sinking in the west and the bright stars of winter are just coming up in the east. Next month will offer better viewing opportunities for what’s up in the sky.

This month in history:
Dec. 3: Pioneer 10 spacecraft makes closest approach to Jupiter – 1973
Dec. 7: Gerard Kuiper born – 1905
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