Category Archives: Features

How Does NASA Change a Spacecraft’s Orbit? Easy as Pi.

Cassini couldn't have orbited Saturn these past ten years without pi!

Cassini couldn’t have orbited Saturn these past ten years without pi!

It’s “Pi Day” (March 14… 3.14… get it?) and, based on how we write the date in the U.S. anyway, all those of a sufficiently geeky nature take a moment to honor the universal usefulness of pi, the glorious Greek letter used to represent the mathematical ratio of a circle’s circumference to its diameter.

The basics of pi were known to the Babylonians over 4,000 years ago, and a method to determine pi to any degree of accuracy needed was developed by Archimedes in the third century BCE. Now, the value of pi has been calculated to many trillions of decimal places and its practical uses have extended far beyond the surface of our planet, helping engineers plot the orbits of planetary spacecraft and even measure the sizes of planets outside our solar system!

In fact NASA uses pi all the time in various extraterrestrial applications… read more:

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Voyager’s Long-Distance Valentine

This is from a post I originally published in 2010. I’ll keep trotting it out until it’s not cool anymore. (Which I don’t think will ever happen.)

Venus, Earth, Jupiter, Saturn, Uranus and Neptune as seen by Voyager 1 in 1990 (Credit: NASA)

On February 14, 1990, after nearly 13 years of traveling the solar system, the Voyager 1 spacecraft passed the orbit of Pluto and turned its camera around to take a series of photos of the planets. The image above shows those photos, isolated from the original series and are left to right, top to bottom: Venus, Earth, Jupiter, Saturn, Uranus, and Neptune.

From that distance, over 4 billion miles from the Sun, the planets each appear as little more than a bright dot against the vastness of interplanetary space. And Voyager was still a long ways off from reaching the “edge” of our solar system, the bubble of energy emitted by the Sun in which all of the planets, moons, and asteroids reside. In fact, Voyager 1 still has an expected five years to go before it crosses that boundary and truly enters interstellar space.*

“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. … There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”

– Carl Sagan

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Interview With the Meteorite Man

Geoff Notkin with meteorite-hunting gear in the Chilean desert (© Geoffrey Notkin)

Geoff Notkin with meteorite-hunting gear in the Chilean desert (© Geoffrey Notkin)

Have you ever seen a meteor streak across the night sky? How about a very bright fireball (aka bolide), one that seemed to disintegrate in front of your eyes or leave a trail of vapor that hung in the air for a few moments? These “shooting stars” are actually tiny bits of rock and dust that exist everywhere in the Solar System, and when they run into Earth’s atmosphere they are slowed down incredibly, resulting in a transfer of energy that releases light and heat — usually enough heat to vaporize the original object entirely. But on occasion a large and/or dense enough object enters the atmosphere and survives the blazing journey to the surface. If it hits land, the meteorite (or its remaining pieces) might one day be discovered by a random traveler, a hiker, a farmer… or a even dedicated  “meteorite man” like Geoff Notkin.

Author, educator, and host of Science Channel’s “Meteorite Men” and Cox7′s STEM Journals, Geoff Notkin has dedicated his life to the study, collection, and dealing of these “inert aliens” from outer space. His Tucson-based company, Aerolite Meteorites, sells some of the specimens that he’s traveled around the world to find, and last week I had the chance to talk with Geoff about his business and his passion and learn more about what got him so interested in meteorites to begin with.

Read the interview here.

“Being a meteorite hunter is probably not the best capital return on your time but it’s a very exciting and rewarding life in every other way.”

– Geoff Notkin, Aerolite Meteorites

Book Review: The Universe in the Rearview Mirror

(Objects in mirror may be more fascinating than they appear.)

Objects in mirror may be more fascinating than they appear.

Physics is hard.

I’m sorry, let me elaborate: physics is really hard. The sharpest minds of our entire species have been hammering away at the fundamental rules of our Universe for the past several hundred years, and while they’ve discovered an incredible lot about the tiniest bits of things that make up… well, everything… it’s still hard. There are still a lot of questions, and a lot to learn and find out, and all of it is just terribly scientific and mathematical and counter-intuitive to anything you might think you know about how stuff works.

Thankfully, author and physicist Dave Goldberg is here to explain it all… or at least give you a working familiarity with the basics. And yes, there are basics. (Even in physics.)

UPDATE: Read on to find out how to win a free copy of the book! 

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The Coolest Calendar You’ll See All Year

The 2013 Year in Space wall calendar is chock-full of astro awesome.

Do you need a new calendar? Of course you do, the year’s almost over. (And if you’d forgotten, well.. you’re welcome.) Of course if you’re reading this post you’re most likely a fan of space exploration, and so you’ll need a calendar that’s going to entertain your fascination about space for a whole year.

This one is it.

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Watch Tonight’s Eclipse Live!

If you can’t see the annular eclipse occurring tonight from where you are, you can watch it LIVE here on LITD! The feed above (providing it’s not over capacity) will be aired from Petroglyph National Monument in New Mexico, beginning at 9 pm Eastern time — right in prime U.S. viewing location! You won’t need to purchase plane tickets or any special eyewear to watch the eclipse safely from your own computer. :)

The National Park Service will feature a live feed of the May 20 eclipse from Petroglyph National Monument in NM. (NPS)

Viewable from the western US, the Pacific and eastern Asia, the eclipse will feature a “ring of fire” at totality created by the Moon passing in front of the Sun — but at a distance where the Sun is not completely covered. (As a result there’s still a lot of UV radiation coming from the Sun, so as always don’t observe the Sun directly without adequate protection.. find out how to safely view eclipses here.)

The video is provided by LiveStream, the National Park Service and the U.S. Department of the Interior.

Find more links to live eclipse feeds on Universe Today here.

NASA: In Pursuit of Light

Can’t see the video below? Click here.

Here’s a new video from the folks at NASA’s Goddard Space Flight Center in Greenbelt, MD that will make you fall in love with the Universe…for the first time, or all over again.

It’s a good reminder that, even though the shuttles are retired, NASA still has its eyes set on the stars (and planets, and moons, and asteroids, and of course on our own little blue world!)

NASA dreams big science. Come for the cool, stay for the music, take away a sense of wonder to share. It’s six minutes from Earth to forever, and you can see it here!

This video is public domain and can be downloaded at: ‪http://svs.gsfc.nasa.gov/goto?10958

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