Apr 01

What’s Up in the Sky

What’s Up in the Sky – April, 2017

Science as a Candle in the Dark*

Holland (the country, not the city) has a rich history when it comes to science, especially astronomy. In 1600 the Italian Roman Catholic scholar, Giordano Bruno, was burned at the stake for his beliefs, among other things, that the universe is home to an infinite number of worlds, some of which may harbor other lifeforms. A few years later Galileo suffered brutality and was placed under house arrest for the remainder of his life for his discoveries and speculations concerning the solar system.

Meanwhile, in Holland, the astronomer Christian Huygens, who held similar beliefs, was showered with honors. The country was an intellectual and cultural center as well as an exploratory power. Improved sailing ships encouraged technology of all kinds and inventions were prized. Light was a topic of universal interest, from the art of Vermeer to the microscope of van Leeuwenhoek and even Huygens’ own wave theory of light. Holland was a leading publisher of books and new ideas led renowned thinkers to reconsider long held beliefs. This was made possible in part by the fact that, while kings and emperors ruled much of the world, the Dutch Republic was governed, more than any other nation, by the people.

One could argue that it was here that the scientific revolution really began, with advances in communication, transportation and medicine vastly improving the well being of billions of people throughout the world in the centuries to follow. The lessons of history have a lot to teach us about the value of scientific inquiry as a way of understanding reality.

It is for this reason that many in the scientific community are greatly disturbed by the growing lack of understanding of how science works. It is not a matter of opinion. It is not up to a vote. It is not what is most popular or even what seems to make the most sense. Many scientists have suffered ostracism and ridicule for their discoveries. Rachael Carson was lambasted by the pesticide industry for her suggestion that DDT was harmful to the environment. Clair Patterson had his funding cut by the petroleum industry for his assertion that people were being poisoned by the lead in automobile exhaust. But today both DDT and leaded gasoline are banned substances.

We did land on the Moon, vaccines do not cause autism, and climate change is real and caused by human activity. We must not pick and choose what scientific theories we accept based on anything other than valid data and its proper analysis. We must not bury our head in the sand by cutting funding for science that is deemed inconvenient, unpopular, or threatening to the status quo. As Neil deGrasse Tyson said, “The good thing about science is that it’s true whether or not you believe in it.” And it all started with our desire to understand what’s up in the sky.

*from The Demon Haunted World, by Carl Sagan, 1995

This month in history:

April 2: First photograph of Sun taken – 1845
April 9: NASA selects original seven Mercury astronauts – 1959
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 24: China becomes the fifth nation to launch its own satellite – 1970
April 25: Deployment of Hubble Space Telescope – 1990
April 28: Eugene Shoemaker is born – 1928

Mar 01

What’s Up in the Sky

What’s Up in the Sky – March, 2017

Planets Everywhere

Planets have been in the news a lot lately. After an historic flyby of Pluto in 2015, the New Horizons spacecraft continues toward its next target, Kuiper Belt object MU69, a small (estimated diameter of 30 miles, maximum), icy world orbiting the Sun beyond the planet Neptune. New Horizons is due to arrive at MU69 on January 1, 2019.

Earlier this month the Juno spacecraft made its fourth close flyby of Jupiter, passing 2700 miles above the planet’s clouds. During the flyby instruments on the spacecraft probed beneath the cloud layers to gather information about the planet’s composition and structure. And there is still action at Saturn where the Cassini spacecraft, launched in 1997 and nearing the end of its mission, continues to make important discoveries as it passes through the gap between the planet and its rings.

These missions help us understand the newly discovered planets orbiting other stars which have been in the news most recently. Last Wednesday, scientists using NASA’s Spitzer Space Telescope announced the discovery of seven Earth-sized planets orbiting around a single star, the first such system to be detected. Three of the planets are located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water. All seven could have water, depending on their atmospheric conditions, but the chances are greatest for the three in the habitable zone. Named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile which discovered the first three last May, this exoplanet system is called TRAPPIST-1. Associate Administrator of the Science Mission Directorate at NASA, Thomas Zurbuchen said, “this discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life.” He went on to echo the sentiments of many astrophysicists by saying, “answering the question ‘are we alone’ is a top science priority”. The Trappist-1 discovery will greatly help scientists in their work to answer that question.

Closer to home, you have undoubtedly noticed bright Venus shining like a beacon with fainter Mars nearby (up and to the left) in the western sky after sunset. Early risers probably have noticed Jupiter gleaming in the southeast before dawn. If you are intrigued by these sights and would like more information regarding our solar system neighbors, check out the Planetary Society at www.planetary.org.

Founded in 1980 by Carl Sagan, Louis Friedman, and Bruce Murray, its mission is to “empower the world’s citizens to advance space science and exploration.” Now headed by Bill Nye (the “Science Guy”), the Planetary Society offers a treasure trove of information and resources for the general public. On its web site you can find articles on everything from current missions to the planets to protecting Earth from asteroid collisions. The Society is also the leading advocate for space science in Washington D.C. Check it out if you are looking for great source of information on what’s up in the sky.

Feb 01

What’s Up in the Sky

What’s Up in the Sky – February, 2017

There’s Much to See When the Sky Clears

February usually does not lend itself to stargazing for several reasons – bad weather, cold nights, and bad weather. It is unfortunate because on clear nights there is quite a bit to see.

You probably have noticed the bright object in the southwest after sunset, and I’m sure regular readers know that it is the planet Venus. And if it is clear tonight you may spot a lovely crescent Moon just to its left. Both objects provide some good viewing during the first half of the month.

On February 3rd Venus reaches its highest point in the sky at sunset, and it will be at its brightest on the 16th. In fact, Venus is so bright it could be visible in the daytime in a very clear sky. Try looking due south about halfway between the horizon and the zenith (directly overhead) around 3:30 p.m. Stand in the shadow of a tree or building and use binoculars at first to locate it, then make a naked eye attempt. It’s a long shot, but I’m sure it would be something you’ve never seen before. It will continue to dominate the southwest sky in the early evening throughout the month.

A more challenging object to observe is the planet Mars, located about five degrees (the width of three fingers held at arm’s length) to the upper left of Venus. You will need binoculars to see it, however, but the Moon might help you find it tonight as it will form a small isosceles triangle the the two planets, with Mars at the top of the triangle. Look around 7:00 p.m. when they are still relatively high above the horizon.

February is also one of the best times of the year, weather notwithstanding, for constellations as well. With two dogs to his left, a rabbit at his feet, and a bull to his right Orion dominates the southern sky for most of the month and is always a favorite for young and old alike. Follow the line formed by the three belt stars down and to the left to Sirius, in the constellation Canis Major and the top two stars left to Procyon in Canis Minor. These are Orion’s two hunting dogs. Hiding safely under his feet is Lupus, the Rabbit, but it is very dim and difficult to see.

Returning to Orion, follow a line from Rigel, lower right, to Betelgeuse, upper left, (his two brightest stars) to the Gemini twins, Castor and Pollux, then continue clockwise to Auriga, the Charioteer, with the bright star Capella and Taurus, the Bull, where you can spot the Pleiades cluster farther west. Also look for the V-shaped cluster of stars, the brightest of which is Aldebaran, the “Eye of the Bull”. Six of these bright stars, Rigel Aldebaran, Capella, Pollux, Procyon and Sirius form the “Winter Hexagon”, a lovely winter sight up in the sky.

This month in history:

Feb. 1: Shuttle Columbia breaks apart during reentry killing all 7 astronauts – 2003
Feb. 6: 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. 23: Light from supernova 1987a reaches Earth – 1987

Jan 03

What’s Up in the Sky

What’s Up in the Sky – January, 2017

2016 – An Historic Year for Astronomy

This is a time of year traditionally known for reflection and anticipation and last year was also been a year of milestones for astronomers. It seems appropriate to look back on major events and discoveries that will make 2016 historic.

Thought by many to be the greatest discovery of the year, as well as one of the greatest in history, was the detection of gravitational waves, ripples in the fabric of spacetime and the result of a cataclysmic event in the distant universe. Although the gravitational waves were detected in September of 2015, it took until February of this year for scientists to verify the observation after much painstaking analysis of the data.

The gravitational waves were a result of a merger of two black holes to produce a single, more massive, black hole, 1.3 billion years ago. The observation confirmed a major prediction of Albert Einstein’s 1915 general theory of relativity and gives astronomers a completely new method by which to study the universe. The discovery was made using the LIGO (Laser Interferometer Gravitational-wave Observatory) detectors, located in Hanford WA and Livingston, LA.

On July 4th, the Juno spacecraft entered into orbit around the giant planet, Jupiter. Although not the first spacecraft to study Jupiter (there have been eight others) nor even the first to orbit the planet (that was Galileo in 1995), Juno is unique in that its orbit is polar rather than equatorial and brings it far closer to the giant planet’s cloud tops than any other spacecraft. With its mission still in its early stages, we can look forward to many great discoveries when Juno probes Jupiter’s deep structure, studies its atmospheric circulation and attempts to learn more about the high-energy physics of its magnetic field.

In September, the European Space Agency’s Rosetta spacecraft ended its mission with a soft landing on the surface of Comet 67P. After two years of study that included ground-breaking observations at extremely close distances, Rosetta has provided scientists with a wealth of data that should keep them busy for years.

The New Horizons spacecraft was still in the news as it finished returning all the data from its flyby of Pluto. One major discovery was that of a massive ice sheet whose top lies 2.5 kilometers below Pluto’s mean elevation. Most likely an impact basin, it may have been formed by a glancing impact of a 200-kilometer body.

And the new year promises to be an exciting one here in the U.S. with next August’s “Great American Solar Eclipse”, an event you will NOT want to miss. It will be the greatest thing you have ever witnessed up in the sky.

Dec 13

Big Science in Small Packages

By Marcus Woo

About 250 miles overhead, a satellite the size of a loaf of bread flies in orbit. It’s one of hundreds of so-called CubeSats—spacecraft that come in relatively inexpensive and compact packages—that have launched over the years. So far, most CubeSats have been commercial satellites, student projects, or technology demonstrations. But this one, dubbed MinXSS (“minks”) is NASA’s first CubeSat with a bona fide science mission.

Launched in December 2015, MinXSS has been observing the sun in X-rays with unprecedented detail. Its goal is to better understand the physics behind phenomena like solar flares – eruptions on the sun that produce dramatic bursts of energy and radiation.

Much of the newly-released radiation from solar flares is concentrated in X-rays, and, in particular, the lower energy range called soft X-rays. But other spacecraft don’t have the capability to measure this part of the sun’s spectrum at high resolution—which is where MinXSS, short for Miniature Solar X-ray Spectrometer, comes in.

Using MinXSS to monitor how the soft X-ray spectrum changes over time, scientists can track changes in the composition in the sun’s corona, the hot outermost layer of the sun. While the sun’s visible surface, the photosphere, is about 6000 Kelvin (10,000 degrees Fahrenheit), areas of the corona reach tens of millions of degrees during a solar flare. But even without a flare, the corona smolders at a million degrees—and no one knows why.

One possibility is that many small nanoflares constantly heat the corona. Or, the heat may come from certain kinds of waves that propagate through the solar plasma. By looking at how the corona’s composition changes, researchers can determine which mechanism is more important, says Tom Woods, a solar scientist at the University of Colorado at Boulder and principal investigator of MinXSS: “It’s helping address this very long-term problem that’s been around for 50 years: how is the corona heated to be so hot.”

The $1 million original mission has been gathering observations since June.

The satellite will likely burn up in Earth’s atmosphere in March. But the researchers have built a second one slated for launch in 2017. MinXSS-2 will watch long-term solar activity—related to the sun’s 11-year sunspot cycle—and how variability in the soft X-ray spectrum affects space weather, which can be a hazard for satellites. So the little-mission-that-could will continue—this time, flying at a higher, polar orbit for about five years.

If you’d like to teach kids about where the sun’s energy comes from, please visit the NASA Space Place: http://spaceplace.nasa.gov/sun-heat/

Astronaut Tim Peake on board the International Space Station captured this image of a CubeSat deployment on May 16, 2016. The bottom-most CubeSat is the NASA-funded MinXSS CubeSat, which observes soft X-rays from the sun—such X-rays can disturb the ionosphere and thereby hamper radio and GPS signals. (The second CubeSat is CADRE — short for CubeSat investigating Atmospheric Density Response to Extreme driving – built by the University of Michigan and funded by the National Science Foundation.) Credit: ESA/NASA

This article is provided by NASA Space Place. With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov to explore space and Earth science!

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