NEWLY DISCOVERED VOLCANO SAME LEAGUE AS OLYMPUS MONS ON MARS

A perspective 3D plot of the topography of the largest single volcano on Earth, Tamu Massif.

A 3-D map of the Tamu Massif formation, which scientists now say is one huge shield volcano

Illustration courtesy IODP

 

“This finding goes against what we thought, because we found that it’s one huge volcano,” said William Sager, a geology professor at the University of Houston in Texas. Sager is lead author in a study about the find that was published this week in the peer-reviewed journal Nature Geoscience.

“It is in the same league as Olympus Mons on Mars, which had been considered to be the largest volcano in the solar system,” Sager told National Geographic.

 

LADEE – Back On Track On Its Way To The Moon

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LADEE as seen Friday night from the east coast

LADEE - ON ITS WAY TO THE MOON

LADEE – pronounced like Laddie – is NASA’s Lunar Atmosphere and Dust Environment Explorer.  It is a robotic mission that will orbit the moon gathering information about the atmosphere and lunar dust.
LADEE was launched late last Friday night from NASA’s Wallops Flight Facility at Wallops Island, Virginia.  Saturday, NASA officials reported that the spacecraft’s reaction wheels which spin to position LADEE in space were suddenly not working.  Engineers have now disabled the safety limits that caused the problem enabling LADEE to continue on course. 

LADEE will orbit Earth several times before heading to the moon, arriving in about 30 days.  It will then orbit the moon for about 100 days or until it runs out of fuel.  LADEE will then crash into the lunar surface continuing to collect data along the way.

The Full Dome Saga Pt. 1: From Mechanical to Digital

The Full Dome Saga Part 1: From Mechanical to Digital

Hello Readers, you are about to embark on a journey through the world of planetarium technology and production. Every Friday for the next few weeks we will explore all things digital planetarium. The first part of the Full Dome Saga is a brief background on the  technological evolution from the traditional planetarium to the digital dome of today. In later posts we will compare production techniques and equipment used for Hollywood movies to that used for planetarium production, animation and rendering techniques, live action capture, and more.

When many people think planetarium, they imagine a dark, domed room with a strange machine in the center. They imagine a mystifying experience where a presenter takes them on a tour of the stars and constellations in our sky. In the last ten years, the digital revolution has taken the planetarium on an interesting journey (which is far from over). With advances in digital projection systems, software and computers, planetaria are transforming into immersive theaters. Using anywhere between one and thirty projectors, a bank of synchronized computers, and sophisticated software, planetaria are pushing the boundaries of possibility for both education and entertainment.

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These digital systems allow presenters to move beyond the traditional night sky star talk. In a digital planetarium you can watch a full dome movie, specially produced to cover the entire dome, providing a “you are there” experience unlike any other. Differing from traditional movie theaters, digital planetaria possess realtime astronomy visualization software. A presenter can simulate and navigate through actual astronomical data in real time, almost like a video game.  Full dome content is still largely CGI, with only small amounts of live action. Where are the IMAX type nature films designed for the immersive planetarium theater experience? They’re coming…. (I hope!)

Here at LASM the Irene W. Pennington Planetarium houses a 4k digital projection system made by a company called Sky Skan. Our image on the dome is created by two projectors (one at the front and the other at the back of the dome). There are four computers sending visual information to each projector, and one computer that stores the surround sound (see picture at left). All of the computers are controlled by a main master computer and a software called Digital Sky and SPICE. In order for everything to run seamlessly (no pun intended) all computers must run simultaneously with no lagging.

Why are there so many pieces? Projecting a 4k video at a normal frame rate requires multiple computers to share the job, each one takes a small piece of the video to send to the projector (allowing everything to run quickly and smoothly). Current projector technology makes it difficult and expensive to cover a large 60-foot dome with a high quality image using a single projector, so we use two. Other planetaria use four, six or more to accomplish this task.

What does 4k even mean anyway? And does frame rate matter? Return next week to learn about how projection and video in the planetarium compares to your HD TV…

Why is the sky blue and why is the sunset red and orange?

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When I was a kid I heard that the sky was blue because it was the reflection off the ocean.  The light from the Sun, which appears white, is actually made up of all colors of the rainbow, when the light enters the atmosphere the colors can become separated (Imagine looking at light through a prism).  We know that bluer light travels in short, tight waves while redder light travels in longer waves. The shorter the wavelength, the more likely the light is to bounce off of an air molecule and become scattered. Blue light is scattered most in our atmosphere.

I also heard, when I was a kid, that when you observe a sunset and you see the shift in color from blue to red that you’re actually seeing the sun’s rays being filtered through the pollution.  Well, that sounds dismal.  It’s also not entirely true.

One of the main factors in determining a sunset’s color is the Earth’s atmosphere. The atmosphere is made up mostly of gases as well as some other molecules and particles thrown in for good measure.  The most common gasses in our atmosphere are nitrogen (78%) and oxygen (21%). The remaining single percent is made up of water vapor and lots of tiny solid particles like dust, soot & ash, pollen, and salt from the oceans.  There are also trace gasses like argon present. Also, depending on where you live, you’ll have to factor in that volcanoes can put large amounts of dust particles high into the atmosphere and pollution can add different gases or dust and soot to the air as well.

The atmosphere of the Earth can be thought of like a filter on a camera lens.

light through a prismLight from a light bulb or the Sun may look white, but it is actually a combination of many colors. When you see light filtered through a prism you’ll see this white light split up into its separate colors, i.e. wavelengths.  White light is the colors of the spectrum blended into each other. rainbowAnd a rainbow that you see in the sky is actually a natural prism effect as rain drops split those different colors up.  The colors have different wavelengths, frequencies, and energies. Violet has the shortest wavelength. Red has the longest wavelength.  The shorter the wavelength means the more powerful the frequency.wavelenghts

So let’s put it all together in how light acts in the air surrounding our planet. Light moves in a straight line until it is messed with (be it gas, dust, ash, etc.). Once something interferes and gets in the way of the light wave it’ll scatter that light in different directions. The probability of light to be scattered by a molecule is proportional its wavelength, so shorter wavelengths of light are scattered much more often than longer wavelengths. In the case of air molecules, the molecules are much smaller than the wavelength of the scattered light, this is called Rayleigh scattering.

 

sunlightpathAs the Sun sets later in the day, the light becomes less and less direct, think of what causes your shadow to be longer in the afternoon than during mid day. During mid day, sunlight is shining almost directly down through the atmosphere, while at the end of the day it is shining through more atmosphere. As the white sunlight travels through more atmosphere, more of the shorter wavelength colors are scattered away from our line of sight. Until finally as the Sun is about to set below the horizon, only red (the visible light with the longest wavelength) remains.