Xyhor-astronomy - Xpand Your Horizons W/ Astronomy & Spacefaring

Chasing the Shadow of Neptune’s Moon Triton

Our Flying Observatory

Our flying observatory, called SOFIA, carries a 100-inch telescope inside a Boeing 747SP aircraft. Scientists onboard study the life cycle of stars, planets (including the atmosphere of Mars and Jupiter), nearby planetary systems, galaxies, black holes and complex molecules in space.

AND in just a few days SOFIA is going on a special flight to chase the shadow of Neptune’s moon Triton as it crosses Earth’s surface!

In case you’re wondering, SOFIA stands for: Stratospheric Observatory for Infrared Astronomy.

Triton

Triton is 1,680 miles (2,700 km) across, making it the largest of the 13 moons orbiting Neptune. Unlike most large moons in our solar system, Triton orbits in the opposite direction of Neptune, called a retrograde orbit. This backward orbit leads scientists to believe that Triton formed in an area past Neptune, called the Kuiper Belt, and was pulled into its orbit around Neptune by gravity. 

The Voyager 2 spacecraft flew past Neptune and Triton in 1989 and found that Triton’s atmosphere is made up of mostly nitrogen…but it has not been studied in nearly 16 years!

Occultations are Eclipse-Like Events

An occultation occurs when an object, like a planet or a moon, passes in front of a star and completely blocks the light from that star. As the object blocks the star’s light, it casts a faint shadow on Earth’s surface. 

But unlike an eclipse, these shadows are not usually visible to the naked eye because the star and object are much smaller and not nearly as bright as our sun. Telescopes with special instruments can actually see these shadows and study the star’s light as it passes near and around the object – if they can be in the right place on Earth to catch the shadow.

Chasing Shadows

Scientists have been making advanced observations of Triton and a background star. They’ve calculated exactly where Triton’s faint shadow will fall on Earth! Our SOFIA team has designed a flight path that will put SOFIA (the telescope and aircraft) exactly in the center of the shadow at the precise moment that Triton and the star will align. 

This is no easy feat because the shadow is moving at more than 53,000 mph while SOFIA flies at Mach 0.85 (652 mph), so we only have about two minutes to catch the shadow!! But our SOFIA team has previously harnessed the aircraft’s mobility to study Pluto from inside the center of its occultation shadow, and is ready to do it again to study Triton!

What We Learn From Inside the Shadow

From inside the shadow, our team on SOFIA will study the star’s light as it passes around and through Triton’s atmosphere. This allows us to learn more about Triton’s atmosphere, including its temperature, pressure, density and composition! 

Our team will use this information to examine if Triton’s atmosphere has changed since our Voyager 2 spacecraft flew past it in 1989. That’s a lot of information from a bit of light inside a shadow! Similar observations of Uranus in 1977, from our previous flying observatory, led to the discovery of rings around that planet!

International Ground-Based Support

Ground-based telescopes across the United States and Europe – from Scotland to the Canary Islands – will also be studying Triton’s occultation. Even though most of these telescopes will not be in the center of the shadow, the simultaneous observations, from different locations on Earth, will give us information about how Triton’s atmosphere varies across its latitudes. 

This data from across the Earth and from onboard SOFIA will help researchers understand how Triton’s atmosphere is distorted at different locations by its high winds and its strong tides!

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Two moons of Uranus: Titania and Oberon. Both moons were discovered by William Herschel in 1787.

Credit: NASA/JPL

A false-color image of the mid-infrared emission from the Great Galaxy in Andromeda, as seen by Nasa’s WISE space telescope.

Credit: NASA/JPL-Caltech/WISE Team

Could StarTram Revolutionize Space Travel? | RealClearScience

StarTram is a game changer, doing away with explosions, propellants, and chemistry in favor of pure physics. It's a shining example of an idea that could take humanity into a new technological era.

While stuck in traffic in 1961, James Powell, a young researcher at Brookhaven National Laboratory came up with the idea of using powerful magnets to lift and propel massive passenger-carrying cars. Over the next seven years, he and his colleague Gordon Danby spent their spare time piecing together a concept. They obtained a patent for the breakthrough in 1968. Powell and Danby’s magnetic levitation, or maglev, technology must have seemed like magic back then, but it is now being used to move large trains at speeds up to 375 miles per hour!

Not content to rest on this sole accomplishment, the 84-year-old Powell now has grander ambitions for his maglev breakthrough. In 2001, he teamed up with George Maise, an aeronautical engineer and 23-year veteran of Brookhaven National Laboratory, to put forth an idea to revolutionize space launches: StarTram.

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Astronomy and Astrophysics: Facts

Here is a list of some curiosities of astronomy and astrophysics. From our solar system to interstellar space.

Rings of Saturn: With an estimated local thickness of as little as 10 m and as much as 1 km, they are composed of 99.9% pure water ice with a smattering of impurities that may include tholins or silicates. The main rings are primarily composed of particles ranging in size from 1 cm to 10 m.

Valhalla (crater): Valhalla is the largest multi-ring impact crater on Jupiter’s moon Callisto and in the Solar System. It is named after Valhalla, the God Odin’s hall in Norse mythology where warriors are taken after death. 

Europa (lineae):  Europa’s most striking surface features are a series of dark streaks crisscrossing the entire globe, called lineae (English: lines). Close examination shows that the edges of Europa’s crust on either side of the cracks have moved relative to each other. The larger bands are more than 20 km (12 mi) across, often with dark, diffuse outer edges, regular striations, and a central band of lighter material. The most likely hypothesis states that the lineae on Europa may have been produced by a series of eruptions of warm ice as the Europan crust spread open to expose warmer layers beneath. The effect would have been similar to that seen in Earth’s oceanic ridges.

Tartarus Dorsa: The western part of Pluto’s northern hemisphere consists of an extensive, highly distinctive set of 500-meter-high mountains informally named Tartarus Dorsa; the spacing and shape of the mountains looks similar to scales or tree bark. 

Mountain in Ceres: Ahuna Mons is the largest mountain on the dwarf planet and asteroid Ceres. It protrudes above otherwise smooth terrain, it is not an impact feature, and it appears to be the only mountain of its kind on Ceres. Bright streaks run top to bottom on its slopes; these streaks are thought to be salt, similar to the better known Cererian bright spots, and likely resulted from cryovolcanic activity from Ceres’s interior. It is named after the traditional post-harvest festival Ahuna of the Sumi Naga people of India.

Pluto has a tenuous atmosphere consisting of nitrogen (N2), methane (CH4), and carbon monoxide (CO), which are in equilibrium with their ices on Pluto’s surface. According to the measurements by New Horizons, the surface pressure is about 1 Pa(10 μbar), roughly one million to 100,000 times less than Earth’s atmospheric pressure. It was initially thought that, as Pluto moves away from the Sun, its atmosphere should gradually freeze onto the surface; studies of New Horizons data and ground-based occultations show that Pluto’s atmospheric density increases, and that it likely remains gaseous throughout Pluto’s orbit.  

Sagittarius A*: Sagittarius A*  is a bright and very compact astronomical radio source at the center of the Milky Way, near the border of the constellations Sagittarius and Scorpius. It is part of a larger astronomical feature known as Sagittarius A. Sagittarius A* is thought to be the location of a supermassive black hole, like those that are now generally accepted to be at the centers of most spiral and elliptical galaxies.

Double Pulsar: PSR J0737−3039 is the only known double pulsar. It consists of two neutron stars emitting electromagnetic waves in the radio wavelength in a relativistic binary system. The two pulsars are known as PSR J0737−3039A and PSR J0737−3039B. It was discovered in 2003 at Australia’s Parkes Observatory by an international team led by the radio astronomer Marta Burgay during a high-latitude pulsar survey.

IC 1101: IC 1101 is a supergiant elliptical galaxy at the center of the Abell 2029 galaxy cluster, approximately 320 megaparsecs (1.04 billion light-years) from Earth. IC 1101 is among the largest known galaxies, but there is debate in the astronomical literature about how to define the size of such a galaxy.

A rogue planet (also termed an interstellar planet, nomad planet, free-floating planet, orphan planet, wandering planet, starless planet, sunless planet, or Planemo) is a planetary-mass object that orbits the galaxy center directly. Such objects have been ejected from the planetary system in which they formed or have never been gravitationally bound to any star or brown dwarf. The Milky Way alone may have billions of rogue planets.

souce: wikipedia

Image credit: NASA/JPL/SwRI, Ted Stryk, John Rowe Animations, commons.wikimedia 

If we ever want a long-distance relationship with aliens, they have to be able to find us.

OSIRIS-REx view of Earth and Moon                      

This color composite image of Earth and the Moon was taken October 2, 2017, 10 days after OSIRIS-REx performed its Earth Gravity Assist maneuver, using MapCam, the mid-range scientific camera onboard the spacecraft. The distance to Earth was approximately 5,120,000 km—about 13 times the distance between the Earth and Moon.

MapCam, part of the OSIRIS-REx Camera Suite (OCAMS) operated by the University of Arizona, has four color filters. To produce this image, three of them (b, v and w) were treated as a blue-green-red triplet, co-registered and stacked. The Earth and Moon were each color-corrected, and the Moon was “stretched” (brightened) to make it more easily visible.

via: The Planetary Society

image: NASA / GSFC / University of Arizona

2017 October 30

Orionid Meteors from Orion Image Credit & Copyright: Lu Shupei

Explanation: Meteors have been shooting out from the constellation of Orion. This was expected, as October is the time of year for the Orionids Meteor Shower. Pictured here, over a dozen meteors were caught in successively added exposures last weekend over Wulan Hada volcano in Inner Mongolia, China. The featured image shows multiple meteor streaks that can all be connected to a single small region on the sky called the radiant, here visible just above and to the left of the belt of Orion, The Orionids meteors started as sand sized bits expelled from Comet Halley during one of its trips to the inner Solar System. Comet Halley is actually responsible for two known meteor showers, the other known as the Eta Aquarids and visible every May. Next month, the Leonids Meteor Shower from Comet Tempel-Tuttle should also result in some bright meteor streaks.

∞ Source: apod.nasa.gov/apod/ap171030.html

evosia Chasing auroras is much like living life: if you show up, always be prepared for the amazing to happen.