Tag Archive: Astronomy


Mercury (MESSENGER)

Mercury is the closest planet to the sun and it is also the smallest planet in the solar system, now that Pluto has been demoted. Until now, Mercury has been the only major body in the inner solar system that has not been orbited by human spacecraft. As of Thursday, NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging probe, aka MESSENGER, (what an acronym!) successfully entered orbit around the planet, after two flybys of Venus, 3 of Mercury and one of Earth itself. There, it will map the surface and study the environment around Mercury. There are a number of mysteries surrounding the planet, including why it has such a large iron core. There are also a number of questions about strange and bizarre terrain found opposite the planet from a huge 1,550 km-wide impact basin.

Mercury’s next visitors will arrive as part of a joint European Space Agency and Japanese Space Agency project, BepiColombo, that is expected to reach the planet in 2019.

Wikipedia: Mercury

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The Moon, near 1st Quarter Phase (rbw)

A few friends have brought to my attention an article that was posted by Yahoo News about the ‘Supermoon’. They were asking what I thought about the possibility that because the March 19th Full Moon will be closer to the Earth than at any time during the past 18 years that we will see all sorts of natural disasters. Apparently, an Astrologer, Richard Nolle (who I have already just given more attention than he deserves) believes that the close proximity of the moon will cause the standard panoply of natural disasters – you know – volcanoes, earthquakes, etc. So what is going on? What is this all about?

Well, for starters, there will hardly be chaos outside of the chaos that already takes place in the world without a ‘Supermoon’. In fact, his statement is false on its face: Clearly the world experienced no major chaos due to the Moon 18 years ago when the Moon was closer than it will be Saturday. Nor do Astronomers recognize the term ‘Supermoon’.

What is true is that the Moon does revolve around the Earth in an elliptical orbit. The Moon typically gets as close to the Earth as 363,100 km (225,600 mi) and as far from it as 405,700 km (252,100 mi). The closest point in the orbit is called perigee while the most distant point is call apogee. These two words come from Greek. Gee refers to the Earth while peri- and apo- mean “near” and “far”, respectively.

The perigee and apogee distances that I mentioned above are not actually constant. All of the objects in the solar system are under the influence of the gravity from all of the other objects in the solar system. The Sun and Jupiter have the strongest gravitational fields in the solar system, and they pull and tug at all of the other objects the most. Meanwhile, all of the objects in the solar system are moving relative to one another. The net effect is that all orbits change slightly over time and it just happens that the Moon will be rather close this coming weekend.

Because the Moon is closer to the Earth at perigee, tides on the Earth are higher. This is because the force of gravity from the Moon is inversely proportional to the its distance, squared, and the Moon’s gravitational pull on Earth is a little more 20% stronger at perigee than it is at apogee. This has nothing to do with the Moon being either Full or New, however. Whether the Full Moon happens while the Moon is at perigee, apogee or at some other point in its orbit depends on the relative angle between the Sun, Earth and Moon – and that changes during the course of the year. Right now, during the Moon is near Full Phase when it is at perigee and by Fall, it will be Full right around apogee.

John Bellini, a geophysicist from the U.S. Geological Survey, mentions that even with the slight fluctuation in the gravitational force from the Moon as it revolves around the Earth, that there is little correlation between lunar perigee and earthquakes on the Earth. That is because the forces that cause plate tectonics are not driven by astronomical sources (and certainly not astrological sources!) – they are driven by currents in Earth’s mantle. There is, however, a noticeable difference in the heights of tides.

Now that you are relieved, I will mention that the Full Moon will look about 8% larger than average and it will look about 14% larger than when it is at Apogee Saturday night, so if the weather is permitting, go out and check it out. The Moon will rise around 7:30pm and it will be high in the sky by midnight or 1am on the 20th, so go out and have a look – it will be pretty!

Sunlight enters the main entrance of New Grange once per year on the Winter Solstice (Cyril Byrnes, via The Irish Times)

Happy St. Patrick’s Day! As people all over celebrate all things Irish today, let’s take a look at a place as old as Ireland itself. New Grange is a huge passage mound in County Meath that dates to 3100 – 2900 BCE, during the Neolithic Period (the New Stone Age). It is part of the Brú na Bóinne archaeological complex, an expansive site that predates the Pyramids at Giza. Roughly 150 passage graves survive today in Ireland and 40 of them are locate at Brú na Bóinne.

The site is huge. Some 550 giant slabs, weighing a total of 200,000 tonnes were quarried from the riverside nearby in order to construct it and transported to the site, all under the power of humans and animals. Its use is uncertain, though most people believe it was a tomb. It does have some astronomical significance as well: Each winter solstice, the sun shines directly into the main passage of the monument, illuminating the far wall.

Wikipedia: New Grange

Electron microscope image of a part of a meteorite from Mars: ALH 84001 (Wikipedia

Two NASA astronomers shocked the world with an announcement in 1996: Alien life discovered in a meteorite from Mars. Though NASA eventually retracted the paper on the face of new evidence that suggested some of the carbonate globules were formed at rather high temperatures that would likely preclude life, the announcement still served to tantalize the public about the prospects of life traveling about in space. We see that even today with major news about a controversy over another potential discovery of life from a meteorite. Unfortunately, the life that was discovered may be due to contamination from the Earth.

Wikipedia: ALH 84001

A Taurus XL Rocket on its last successful launch in 2004 (Wikipedia)

Failures on Climate Change

NASA lost another payload that was to be launched to orbit on an Orbital Sciences Taurus XL rocket on Friday because the nose cone failed to separate en route to orbit. The rocket was carrying the Glory satellite, a member of a cluster of satellites to study climate change, in this case by observing aerosol abundances in the atmosphere. Aerosols reflect light from the Sun before the light can be absorbed by the ground. Three out of the last four launches on the Taurus XL have failed for the same reason, and two of them were carrying a satellite that was intended to study Climate Change and the third was to study ozone in the atmosphere. This has led to some people to discuss conspiracy theories. Regardless, there is now a good deal of concern that important measurements needed to better forecast climate change will not occur in a timely fashion due to these launch failures and due to the $600 million cuts to NASA climate observational programs by Congressional Republicans (who do not believe in Climate Change, but do believe in Biblical Unicorns). NASA is trying to defend itself from claims of incompetence, which frankly happens a lot when budget cuts lead to cutting corners. Says Rick Obenschain, Deputy Director of NASA’s Goddard Space Flight Center:

“To make any connection between our investigation of the 2009 … mishap and Friday’s failure of the Glory launch at this time would be purely speculative and wholly inappropriate.”

Of course. It would be wholly inappropriate to consider that a mishap due to one failure of a nose cone separation with another on the same launch system carrying the same type of satellite. That is the statement of a bureaucrat trying to defend his bureau.

During the presentation of the results of the inquiry, physicist and Nobel Laureate Richard Feynman embarrassed the NASA community with a simple and elegant description of the problem that destroyed the Space Shuttle Challenger – stiffness in seals on the rocket boosters at low temperatures. Watch here:

His work on the committee led to another perspective, encapsulated in bullet points from the Challenger Disaster investigation

Shrinking and unpredictable budgets became problematic. NASA was consistently asked to do more with less (the eternal hope of budget administrators everywhere).

The Reagan administration put more and more pressure on NASA to keep a regular schedule of launches. President Reagan’s dream of space weapons was dependent on keeping to the schedule. Launch delays became more problematic for NASA administrators.

The “can-do attitude” of the 1960s became a “make-do attitude.” Cost-saving mechanisms became the norm. Engineer salaries did not keep pace with inflation, and out-sourcing became commonplace.

Budget cuts made redundant safety systems less desirable. If the engineers found a mechanical problem, the classification of the problem became not just an issue of safety, but also of budget. So if a mechanical problem occurred, but didn’t immediately endanger life, it could be classified as a “concern” rather than a “problem.” In other words, if it didn’t work like we expected, but nothing bad happened, then we’ll just ignore it.

The o-rings had been a concern before. Cracks had been found in the o-rings after previous flights. However, since no disasters had happened, the cracks were seen as “normal,” rather than a “problem.”

–Courtesy of problems.olhoff.com

In essence (and I’m paraphrasing Feynman here): Continued budget cuts eliminate redundant checks and balances in systems that were there to ensure safety. Cutting back too much on the budget for an exploratory program like NASA guarantees there will be problems.

We should understand that the Challenger Disaster occurred during the lifetimes of all of the Members of Congress. It is known that scaling back programs leads to technical trouble. Therefore, scaling back Climate funding is a useful fait accompli for a Climate Change denying Congressman who calls for deep cuts to science budgets. The subsequent claim that either the net result was unexpected or that they have confidence that an organization can do more with less only serves to led plausible deniability to the Congressman. Yet most Climate Change denying Congressmen receive a good deal of campaign funding from oil companies that would be adversely impacted should there be a viable renewable alternative to oil – and these same companies lobby Congress intensely on the issue of Climate Change.

In short – whether by direct or indirect interference is no matter but the oil companies who hold the GOP purse strings are setting back Climate Change research upon which rely in order to better understand human impact on its own surroundings.

3753 Cruithne (Powell Observatory, via Wikipedia)

Everyone has seen the Moon, Earth’s only natural satellite, in the sky going through its phases as it revolves around our planet, but there are also other classes of objects in space that have orbits similar to Earth. Some of these objects revolve around the Sun, but pass very close to the Earth on regular intervals due to an orbital resonance. The result, when viewed from Earth is an oddly-shaped orbit centered on a point near Earth. One of these objects is the asteroid 3753 Cruithne, one of five known quasi-satellites of Earth.

Cruithne is a small asteroid, roughly 5km in diameter, it is never bright in the sky and it requires a 12-inch telescope to view it. During close approaches, Earth’s gravity alters its orbit slightly so Cruithne spends a good deal of time either catching up to the Earth or falling behind it until the next close pass alters its orbit in the exact opposite way. The pattern is stable for hundreds of millions of years.

Wikipedia: 3753 Cruithne

VY Canis Majoris highlights this paradigm-shifting video (via blangled on YouTube)

We have heard from elementary school that the Sun is an average star. Some people may be bothered by the fact that there is very little about the Sun that is superlative, but it should not bother you too much. Other people are curious about just how large other stars can be. At the moment, a red supergiant star, VY Canish Majoris holds the record. If placed inside our Solar System, the star would extend to the orbit of Saturn! At 30-40 times the mass of the Sun, it is also a very massive star, though it has an amazingly low density, about 1/10,000th the density of air at sea level on a warm day. Click on the image to see just how large CY Canis Majoris is relative to the Sun, its planets, and other stars.

Wikipedia: VY Canis Majoris

Comet 9P/Tempel I (Deep Impact, NASA, JPL, University of Maryland)

Welcome to the nucleus of Comet 9P/Tempel I, the first object that was visited (and struck by) NASA’s Deep Impact space probe. The 7.6×4.9km hunk of rock, dust and ice revolves around the Sun roughly between the orbits of Mars and Jupiter once every 5.68 years. After sending a washing machine-sized impactor to crash into the surface to study the material kicked off the comet, the Deep Impact probe continued through space on its way to a rendezvous with Comet Hartley 2 in November, 2010 under the name EPOXI. Another spacecraft NExT (formerly Stardust) has just revisted Comet Tempel I on February 15th.

Check it out at Wikipedia.

Solar Flare (NASA Goddard Space Flight Center)

A large X-Class Solar Flare occured early Tuesday and an image from the Solar Dynamics Observatory posted on Astronomy Picture of the Day shows it. Considering the rate of travel of the solar wind, there may be Aurorae tonight that could be visible from mid-latitudes (if it is not cloudy).

The Supreme Council of the Armed Forces of Egypt mentioned Tuesday that work will soon begin on a new national constitution. Efforts continue to encourage protestors back to work. They are now arguing for labor rights and higher pay. After protests were put down by force in Iran, Iranian MPs call for the death penalty for opposition group leaders Mehdi Karroubi and Mirhossein Mousavi. This time, the US is strongly and quickly standing behind the protestors. On the other hand, the US reaction is not likely to be as eager in Yemen, where protests have continued into their fifth day. Protestors are not terribly happy about the US-back President, nor are they very happy about the American drone strikes against Yemeni nationals as part of the “War on Terror”. All of the strike activity continues to bring up the question “Where next?” While all eyes are on Pakistan, whose push for nuclear arms gives it one of the larger nuclear arsenals in the world, fears are rising that some nuclear weapons may be lost in this very unstable country. Oh, and one source of angst against the government in Pakistan is its cooperation with the US drone attacks that have led to a large number of civilian deaths. But Democracy is winning the day as protests continue in Baharain, despite the King’s gifting every family in the country with $3,000 to soothe the nerves. Sadly, America finds itself in the ironic situation where it is not the self-avowed bastion of democracy it once claimed itself to be. Perhaps this is a problem with marketing.

Few Americans know very much about the drone strikes in different countries, but it turns out they may not care. Many Americans, including a majority of Republican primary voters are preoccupied with whether Barack Obama is an American citizen. (He is.) Despite the falsity of the claim, House Speaker John Boehner and Majority Leader Eric Cantor do not believe it is their job to correct their constituents. This comes even as Republicans plan to attack the 14th Amendment which argues that anyone born on American soil is a US citizen. This seemingly innocuous guarantee prompted an outcry from Representative Louie Gohmert (R-Tx) last summer. On the other hand, they are not very helpful on the economy either. After the Republicans campaigned on jobs, jobs, jobs, John Boehner says that if the proposed draconian cuts to the federal budget cost jobs, “so be it.” The loss of more jobs, would of course limit future federal revenue, creating more budgetary problems in the future.

Despite several costly provisions, the House succeeded on its third attempt in one week to extend several provisions of the PATRIOT Act. 27 Republicans voted against it and 65 Democrats voted for the extension which includes “roving wiretap” court orders and allows authorities to seize “any tangible things” in a search. See how your Representative voted here.

In other portions of the US Government, Supreme Court Justices Scalia and Thomas are taking heat for failing to recuse themselves from apparent conflicts of interest revolving around their involvement with the Koch Brothers prior to the Citizens United ruling last year, in which the two justices argued slavishly in favor of corporate interests such as those of the ultra-libertarian Koch brothers. Clarence Thomas’ wife is also head of a Tea Party group. While many Tea Party groups are financed in part by the billionaire Koch brothers, Clarence Thomas has failed to report income from his wife’s political activities for more than a decade now, prompting the Supreme Court Justice to uncomfortably claim that he did not understand the corresponding tax law when the news became public. Oops.

The US government is asking Twitter to divulge information pertaining to the whereabouts and names of people associated with WikiLeaks in a move that bodes poorly for internet privacy rights. This and other issues related to first amendment rights may be reasons that Julian Assange has brought civil liberties advocate Alan Dershowitz onto his legal defense team.

The New York Stock Exchange is being purchased by the German Börse, all while Republicans across the nation continue to argue against Socialism. Not to worry, the two leading shareholders in the Börse run an American hedge fund. The NYSE is struggling to maintain profitability by leaving retail investments for derivatives trading.

In Space, the probe NExT (formerly Stardust) makes history as it flies past its second comet, Tempel 1. It was first launched toward Comet Wild 2 12 years ago and has very limited fuel remaining onboard.

Aurora update

X-Ray image of the Sun, February, 15, 2011. (NOAA Space Weather Prediction Center)

Above is the most recent image of the Sun’s lower atmosphere in X-Rays. Compare with a similar image from Sunday. One thing that you can notice is the rotation of the Sun on its axis – it rotates about once per month at the equator, but rotates a bit more slowly at the poles.

Solar X-Ray flux, February, 2011 (NOAA Space Weather Prediction Center)

The X-Ray flux measurements from the GOES-15 satellite shows a number of small bursts from the Sun during the past couple of days, but nothing major.

Auroral Oval, Norther Polar Map (NOAA Space Weather Prediction Center)

In fact, a look at the Earth’s polar regions shows that the Auroral Ovals are roughly normal. You would be able so see the aurorae if the yellow circle were to lie near your portion of the world. As of now, it appears that viewing is limited to northern Canada, Norway, Greenland and northern Siberia. For more details, please see NOAA’s Space Weather Prediction Center.

Aurorae for Valentines Day?

The Sun has an 11-year cycle of activity over which the number of sunspots and solar flares oscillates with time.  It is making a late return to activity from the most recent Solar Minimum, when its level of activity is quite low. During levels of heightened activity, the sun produces solar flares that send charged particles out into space and sometimes these particles collide with the earth’s atmosphere, producing aurorae.

Recent observations by GOES-15 (Geostationary Operational Environmental Satellite), which is operated by the US National Oceanic and Atmospheric Administration (NOAA), indicate that a solar flare may be possible during the next few days.

GOES-15 X-Ray image of the Sun's lower atmosphere

Above is an image of the Sun today, from the high-energy X-Ray part of the electromagnetic spectrum. The bright spot just below and to the left of the center of the Sun’s disk is hot gas that lies directly above an active sunspot group. The extended halo around the Sun is hot gas in the lower atmosphere, the bottom portion of the solar Corona. If a solar flare were to go off, it would head right toward the Earth and below, you can see that the amount of activity, indicated by the X-Ray flux levels, have increased over recent days.

Solar X-Ray surface flux, February 2011 (NOAA Space Weather Prediction Center)

Most solar flares do not do much harm to human activity, though they can produce radio and cell phone interference. On rare occasions, strong solar flares might damage satellites or bring down the power grid. It is much more likely that when the charged particles from solar flares collide with Earth’s atmosphere, we will be treated to a nice display of aurorae at night. The best time and place to see the aurorae are at mid- to high-latitudes on a clear, dark night between 10pm and 2am. See the NOAA Space Weather Prediction Center website or Space Weather.com for updates on solar activity.