## Sunday, September 30, 2012

### Curiosity Finds Old Streambed on Martian Surface

NASA's Curiosity rover found evidence for an ancient, flowing stream on Mars at a few sites, including the rock outcrop pictured here, which the science team has named "Hottah" after Hottah Lake in Canada’s Northwest Territories.

Source: NASA

### Comet shining 15 times brighter than moon will fly by Earth

A comet which shines 15 times brighter than the moon and potentially visible in broad daylight will fly by the Earth next year, giving humans a chance to witness one of the most spectacular events.

Comet ISON is visiting the inner solar system and is set to put on spectacular views for the Northern Hemisphere across November and December in 2013 as it heads toward the sun, according to reports.

The comet, discovered by astronomers in Russia using the International Scientific Optical Network telescope, will pass within two million miles of the sun's surface.

The comet, researchers say, is supposed to be on a 'parabolic' orbit which means it probably originated from the outer skirts of the solar system from the Oort cloud which is a mass of icy debris which lies 50,000 times further from the sun than the Earth.

It is currently moving inwards from beyond Jupiter, and as it approaches the Earth, the 'dirty snowball' could produce a dazzling display, burning brighter than the moon and potentially being visible in broad daylight.

### Question 91: 30 September 2012 (Week 40)

Q91: How many craters are there on the Moon ?

A90: The Main Asteroid Belt is located between Mars and Jupiter
It contains many millions of rocky objects and dust particles, and the dwarf planet Ceres.

### Bhāskara II

Bhāskara (also known as Bhāskara II and Bhāskarāchārya ("Bhāskara the teacher"), (1114–1185), was an Indian mathematician and astronomer. He was born near Vijjadavida (Bijāpur in modern Karnataka). Bhāskara is said to have been the head of an astronomical observatory at Ujjain, the leading mathematical center of ancient India. He lived in the Sahyadri region.
Bhāskara and his works represent a significant contribution to mathematical and astronomical knowledge in the 12th century. He has been called the greatest mathematician of medieval India.His main work Siddhānta Shiromani, (Sanskrit for "Crown of treatises,") is divided into four parts called LilāvatiBijaganitaGrahaganita and Golādhyāya. These four sections deal with arithmetic, algebra, mathematics of the planets, and spheres respectively. He also wrote another treatise named Karan Kautoohal.
Bhāskara's work on calculus predates Newton and Leibniz by half a millennium. He is particularly known in the discovery of the principles of differential calculus and its application to astronomical problems and computations. While Newton and Leibniz have been credited with differential and integral calculus, there is strong evidence to suggest that Bhāskara was a pioneer in some of the principles of differential calculus. He was perhaps the first to conceive the differential coefficient and differential calculus.
Bhaskaracharya was born into a family belonging to the Deshastha Brahmin community. History records his great-great-great-grandfather holding a hereditary post as a court scholar, as did his son and other descendants. His father Mahesvara was as an astrologer, who taught him mathematics, which he later passed on to his son Loksamudra. Loksamudra's son helped to set up a school in 1207 for the study of Bhāskara's writings.

His Work :

## Friday, September 28, 2012

### Bhāskara I

Bhāskara (c. 600 – c. 680) commonly called Bhaskara I to avoid confusion with the 12th century mathematician Bhāskara II) was a 7th century Indian mathematician, who was apparently the first to write numbers in the Hindu-Arabic decimal system with a circle for the zero, and who gave a unique and remarkable rational approximation of the sine function in his commentary on Aryabhata's work. This commentary, Āryabhaṭīyabhāṣya, written in 629 CE, is the oldest known prose work in Sanskrit on mathematics and astronomy. He also wrote two astronomical works in the line of Aryabhata's school, the Mahābhāskarīya and the Laghubhāskarīya.

He was "probably a Marathi astronomer". He was born at Bori, in Parbhani district of Maharashtra state in India in 7th century.
His astronomical education was given by his father. Bhaskara is considered the most important scholar of Aryabhata's astronomical school. He and Brahmagupta are one of the most renowned Indian mathematicians who made considerable contributions to the study of fractions.

Source: ISRO

### How to See Uranus in Telescopes on Opposition

The planet Uranus reaches opposition in Pisces on Saturday, Sept. 29, 2012, and will be visible all night.
CREDIT: Starry Night Software

How to see Uranus

In binoculars, Uranus is indistinguishable from a star. Look for it currently in the constellation Pisces.

### Question 90: 28 September 2012 (Week 39)

Q90: Where is the Asteroid Belt?

A89: Pluto is not a planet because it is way too small, and it doesn't meet the necessary requirement needed to be a planet.

The requirements are:

It needs to be in orbit around the sun--Yes, Pluto does orbit the sun.

It needs to have enough gravity to pull itself into a spherical shape -- Pluto has sufficient gravity to have become spherical. (This is called hydrostatic equilibrium, by the way.)

It needs to have "cleared the neighborhood" of its orbit -- Uh oh. Here's the "problem" with Pluto. According to this IAU rule, Pluto is not a planet.

### Mouth of Giant Black Hole Measured for First Time

This image from a simulation shows an energy jet launched from a spinning black hole surrounded by a disk of accreting material. The black hole is spinning at half the maximum rate, and its mass is that of the black hole at the center of the M87 elliptical galaxy. The central black hole 'shadow' due to extreme light bending is apparent in this simulation.CREDIT: Avery E. Broderick (University of Waterloo/Perimeter Institute)

For the first time, scientists have peered to the edge of a colossal black hole and measured the point of no return for matter.
A black hole has a boundary called an event horizon. Anything that falls within a black hole's event horizon — be it stars, gas, or even light — can never escape.

### Where Water Flowed Down-Slope on Mars

This image shows the topography, with shading added, around the area where NASA's Curiosity rover landed on Aug. 5 PDT (Aug. 6 EDT). Higher elevations are colored in red, with cooler colors indicating transitions downslope to lower elevations. The black oval indicates the targeted landing area for the rover known as the "landing ellipse," and the cross shows where the rover actually landed.

### NASA Rover Finds Old Streambed on Martian Surface

NASA's Curiosity rover found evidence for an ancient, flowing stream on Mars at a few sites, including the rock outcrop pictured here, which the science team has named "Hottah" after Hottah Lake in Canada’s Northwest Territories. Image credit: NASA/JPL-Caltech/MSSS

This set of images compares the Link outcrop of rocks on Mars (left) with similar rocks seen on Earth (right). Image credit: NASA/JPL-Caltech/MSSS and PSI

NASA's Curiosity rover mission has found evidence a stream once ran vigorously across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence -- images of rocks containing ancient streambed gravels -- is the first of its kind.

## Thursday, September 27, 2012

### Buddhist ‘Iron Man’ found by Nazis is from space

ELMAR BUCHNER
A Buddhist statue brought to Germany from Tibet by a Nazi-backed expedition has been confirmed as having an extraterrestrial origin.
Known as the ‘iron man’, the 24-cm high sculpture may represent the god Vaiśravaṇa and was likely created from a piece of the Chinga meteorite that was strewn across the border region between Russia and Mongolia between 10,000 and 20,000 years ago, according to Elmar Buchner of the University of Stuttgart, and his colleagues.
In a paper published in Metoritics & Planetary Science, the team reports their analysis of the iron, nickel, cobalt and trace elements of a sample from the statue, as well as its structure. They found that the geochemistry of the artefact is a match for values known from fragments of the Chinga meteorite. The piece turned into the ‘iron man’ would be the third largest known from that fall.
Given the extreme hardness of the meteorite – “basically an inappropriate material for producing sculptures” the paper notes – the artist or artists who created it may have known their material was special, the researchers say. Buchner suggests it could have been produced by the 11th century Ben culture but the exact origin and age of the statue – as opposed to the meteorite it is made from – is still unknown. It is thought to have been brought to Germany by a Nazi-backed expedition to Tibet in 1938-39. The swastika symbol on the piece – a version of which was adopted by the Nazi party – may have encouraged the 1938 expedition to take it back with them.
“While the first debris was officially discovered in 1913 by gold prospectors, we believe that this individual meteorite fragment was collected many centuries before,” said Buchner in a statement. “The Iron Man statue is the only known illustration of a human figure to be carved into a meteorite.”
Although this item may be the only known human figure carved into a rock fallen to earth, other meteorites have also been used by many religions across the world. A 15-ton example in North America called theWillamette meteorite is sacred to some native Americans, while some have suggested that the Black Stone in the Kaaba in Mecca is a meteorite.
Source: http://blogs.nature.com

Number 6: Computerized Telescopes
Many telescopes available today employ electronics, the main purpose of which is to help you locate objects in the sky. So called "Go to" telescopes locate things for you (you dial them up on a hand held controller). A second type (less common) type of computerized teelescope is called "push to". These will also help you find objects, but you physically move the scope while looking at a readout that guides you to your desired target.

A88: The largest asteroid used to be Ceres. Although it is in the asteroid belt, it is a sphere shape and is now a dwarf planet not an asteroid. It is 620 miles in diameter and contains nearly a third of all the mass of the asteroid belt combined. The new largest asteroid is Vesta at 530 miles mean diameter it has only 9% of the mass in the asteroid belt. While being considered for dwarf planet-hood, a mass below guidelines for hydrostatic equilibrium, and a large crater on the south pole breaking its spheroid shape have so far kept it off the list.

### India's Communication Satellite GSAT-10 to be launched on September 29, 2012

GSAT-10 satellite, ISRO's 101st space mission, is ready to be launched from the Kourou launch base in French Guyana. GSAT-10, weighing 3400 kg at the lift off, is the heaviest that ISRO has built. GSAT-10 has been integrated with the Ariane-5 launch vehicle along with co-passenger communication satellite ASTRA-2F awaiting the launch scheduled at 0248 hrs on September 29, 2012 (IST). Necessary arrangements are being done for live telecast of the launch from Kourou Launch Base through Doordarshan

Close-up view of GSAT-10 with one of the antennas partially deployed
About 31 minutes after lift off, GSAT-10 would be injected in a Geosynchronous Transfer Orbit with a perigee of 250 km and an apogee of about 36,000 km. From there, the satellite would be moved to Geostationary Orbit (circular 36,000 km above equator) by using the satellite propulsion system in a three step approach. After this, the solar panels and antennas would be deployed. In the next few weeks, the payload would be turned on to perform a series of extensive In-orbit Tests. The satellite is expected to be operational by November 2012. GSAT-10 satellite will be positioned at 83 deg East orbital location along with INSAT-4A and GSAT-12. The nominal operational life of GSAT-10 is expected to be 15 years.

Source: http://indianspacestation.com/

### Uranus at Opposition on September 29

September 29: Uranus at Opposition

The blue-green planet will be at its closest approach to Earth and its face will be fully illuminated by the Sun. This is the best time to view Uranus. Due to its distance, it will only appear as a tiny blue-green dot in all but the most powerful telescopes.

Also See: Upcoming Events

### List of Large Asteroids by Diameter

The number of bodies grows rapidly as the size decreases. Based on IRAS data there are about 140 main-belt asteroids with a diameter greater than 120 km. For a more complete list, see List of Solar System objects by size.
The inner asteroid belt (defined as the region interior to the 3:1 Kirkwood gap at 2.50 AU) has few large asteroids. Of those in the above list, only 4 Vesta, 19 Fortuna, and 7 Iris orbit there.

Source: wikipedia

### Question 89: 27 September 2012 (Week 39)

Q89: Why Pluto is not considered as a planet now?

A88. The largest asteroid used to be Ceres. Although it is in the asteroid belt, it is a sphere shape and is now a dwarf planet not an asteroid. It is 620 miles in diameter and contains nearly a third of all the mass of the asteroid belt combined. The new largest asteroid is Vesta at 530 miles mean diameter it has only 9% of the mass in the asteroid belt. While being considered for dwarf planet-hood, a mass below guidelines for hydrostatic equilibrium, and a large crater on the south pole breaking its spheroid shape have so far kept it off the list.

### Best Photo of Pluto from Earth Snapped by Hawaii Telescope

This photo of Pluto (right) and its largest moon Charon is the best visible-light photo of the dwarf planet ever taken from Earth. It was taken by the North telescope at the Gemini Observatory using the speckle imaging technique for better clarity. Image released Sept. 26, 2012., CREDIT: Gemini Observatory/NSF/NASA/AURA

A ground-based telescope has snapped the sharpest image yet of Pluto and its moon Charon taken in visible light from Earth.

## Wednesday, September 26, 2012

### Question 88: 26 September 2012 (Week 39)

Q88: Which is Largest Asteroid known in Solar System?

A87: The outer planets are those planets in the Solar System beyond the asteroid belt, and hence refers to the gas giants, which are in order of their distance from the Sun:
• Jupiter is the largest planet in the Solar System, with distinct bands and four very large satellites.
• Saturn is the second largest planet, with a large and bright ring system.
• Uranus was discovered in 1781. It is tilted almost onto the plane of its orbit.
• Neptune was discovered in 1846 as a result of its perturbations of Uranus.
The outer planets all have ring systems, although all but Saturn's are faint.

### NASA Opens Accreditation to Social Media for Spacex Launch

NASA is inviting social media users to apply for credentials for the Oct. 7 launch of the first contracted cargo resupply flight to the International Space Station under NASA's Commercial Resupply Services contract.

The SpaceX Falcon 9 rocket is targeted to liftoff at 8:34 p.m. EDT from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. A back up launch opportunity is available on Oct. 8.

### Lunar Reconnaissance Orbiter Explores the Moon in 3-D

Lobate scarps (a type of cliff) on the moon are found mostly in the highlands, and are relatively small and young. Scientists propose that they form as result of fracturing of the crust as the moon shrinks. Why is the moon shrinking? As the core slowly cools portions freeze from a liquid to a solid thus taking up less volume. Since the lobate scarps are small, hundreds of meters to several kilometers in length, and 10 to 50 meters in height, they must be young; otherwise everyday small meteor bombardment would have obliterated them. (Credit: NASA/Goddard/Arizona State University)

Scientists using the camera aboard NASA's Lunar Reconnaissance Orbiter are acquiring stereo images of the moon in high resolution (0.5 to 2 meters/pixel) that provide 3-D views of the surface from which high resolution topographic maps are made. The Lunar Reconnaissance Orbiter Camera Narrow Angle Camera (LROC NAC) team from the University of Arizona and Arizona State University are currently developing a processing system to automatically generate anaglyphs from most of these stereo pairs. An anaglyph is an image that can be viewed in 3-D using red-blue/green glasses.

LROC acquires stereo images by targeting a location on the ground and taking an image from one angle on one orbit, and from a different angle on a subsequent orbit.

Anaglyphs are used to better understand the 3-D structure of the lunar surface. The LROC NAC anaglyphs make lunar features such as craters, volcanic flows, lava tubes and tectonic features jump out in 3-D. LROC NAC anaglyphs will make detailed images of the moon's surface accessible in 3-D to the general public. The anaglyphs will be released through the LROC web site at http://lroc.sese.asu.edu/ and the NASA LRO web site at www.nasa.gov/lro as they become available.

### Farthest-Ever View of the Universe

Like photographers assembling a portfolio of best shots, astronomers have assembled a new, improved portrait of mankind's deepest-ever view of the universe.

(Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team)

Called the eXtreme Deep Field, or XDF, the photo was assembled by combining 10 years of NASA Hubble Space Telescope photographs taken of a patch of sky at the center of the original Hubble Ultra Deep Field. The XDF is a small fraction of the angular diameter of the full moon.

## Tuesday, September 25, 2012

### Question 87: 25 September 2012 (Week 39)

Q87: Which Planets are known as Outer Planets of solar system?

A86: The inner planets are the planets in the inner part of the Solar System that orbit closest to the sun. The 4 inner planets are Mercury, Venus, Earth, and Mars. There are a number of differences between the inner and outer planets aside from location. The inner planets are composed mostly of rock, while the outer planets are gas giants. Generally, inner planets are both smaller and denser than their counterparts.

### 1000 Fermi Bursts!

The gamma-ray burst monitor (GBM) instrument on Fermi detected its 1000th gamma-ray burst today! This figure from Valerie Connaughton shows the location on the sky of these 1000 cosmic explosions.

The 1000th burst was detected at 21:03 UT on September 21. It lasted for around 3 seconds, and consisted of a single large pulse of gamma-rays. It was automatically detected on board the observatory by the GBM and an alert was sent to the ground, that was then relayed to a worldwide team of astronomers in less than 15 seconds.

### Curiosity Finishes Close Inspection of Rock Target

This image shows the robotic arm of NASA's Mars rover Curiosity with the first rock touched by an instrument on the arm. Image credit: NASA/JPL-Caltech

NASA's rover Curiosity touched a Martian rock with its robotic arm for the first time on Sept. 22, assessing what chemical elements are in the rock called "Jake Matijevic."

After a short drive the preceding day to get within arm's reach of the football-size rock, Curiosity put its Alpha Particle X-Ray Spectrometer (APXS) instrument in contact with the rock during the rover's 46th Martian day, or sol. The APXS is on a turret at the end of the rover's 7-foot (2.1-meter) arm. The Mars Hand Lens Imager (MAHLI), on the same turret, was used for close-up inspection of the rock. Both instruments were also used on Jake Matijevic on Sol 47 (Sept. 23).

### First Two Webb Telescope Flight Mirrors Delivered to NASA

Technicians and scientists check out one of the Webb telescope's first two flight mirrors in the clean room at NASA's Goddard Space Flight Center in Greenbelt, Md. Credit: NASA/Chris Gunn

The first two of the 18 primary mirrors to fly aboard NASA’s James Webb Space Telescope arrived at NASA’s Goddard Space Flight Center in Greenbelt, Md.

The mirrors are going through receiving and inspection and will then be stored in the Goddard cleanroom until engineers are ready to assemble them onto the telescope's backplane structure that will support them.

### NASA's Chandra Shows Milky Way is Surrounded by Halo of Hot Gas

Astronomers have used NASA's Chandra X-ray Observatory to find evidence our Milky Way Galaxy is embedded in an enormous halo of hot gas that extends for hundreds of thousands of light years. The estimated mass of the halo is comparable to the mass of all the stars in the galaxy.

## Monday, September 24, 2012

### Varāhamihira-Astronomer, Astrologer & Mathematician

Varāhamihira was an astronomer and mathematician who studied and Indian astronomy as well as the many principles of Greek, Egyptian, and Roman astronomical sciences.

He was  also known as Varaha or Mihira, was an who lived in Ujjain. He is considered to be one of the nine jewels (Navaratnas) of the court of legendary ruler Vikramaditya.

He was the first one to mention in his work Pancha Siddhantika that the ayanamsa, or the shifting of the equinox is 50.32 seconds.

Number 5: What Brand Telescope is Good?

In the beginner telescope market, this question has become clouded in the last 15 years or so (the good news is that there are more choices than ever before and plenty of great beginner scopes). Meade and Celestron are two major telescope companies; in years gone by all the telescopes offered by these companies were good to excellent. That has changed today, unfortunately the name Meade or Celestron on a telescope no longer guarantees that the scope is a good one.

### Good Website for Kids - Space Science for Kinds

KIDS SPACE
• STARChild
http://starchild.gsfc.nasa.gov/docs/StarChild/StarChild.html

### SpaceX readies cargo trip to make history

Cargo resupply is about to make the history books. On Oct. 7, the Dragon spacecraft of SpaceX, a private company, will be launched from NASA's Cape Canaveral complex. The mission will give new meaning and excitement to the task of hauling cargo.

### Escape Velocity - Definition

In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero. It is the speed needed to "break free" from a gravitational field without further propulsion.
For a spherically-symmetric body, escape velocity is calculated by the formula
$v_e = \sqrt{\frac{2GM}{r}},$

### BRIEF OF INDIAN ASTRONOMY

India's contribution to the science of astronomy is priceless. From Aryabhata to Bhaskara to Chandrasekhara Samanta, Indian astronomers and astronomy raconteurs can be credited with interesting theories and discoveries. The detailed mathematical treatment of the science of astronomy can be traced back to around 400 A.D, but the origin of the science itself can be traced back to a much earlier period. Some references regarding nakshatras, solar and lunar months etc., are available in the Vedas, and more details are available in the puranas. The earliest astronomical text available is the 'Vedanga-Jyothisham ' (1200 BC). As the name itself suggests, this text is a part of the Vedic literature.

Number 4: Telescope Quality

As far as beginner telescopes are concerned, there are many telescopes on the market that are best avoided. Fortunately there are more great choices today than ever before (and at very reasonable prices). Ideally you will spend $500 to get started with an excellent package, however I know that this is out of reach for many. Fortunately there are some nice choices in the$100 range (stick with the ones I recommend however, do not buy any old \$100 scope you find)! Many beginner telescopes make performance claims that are preposterous, and are of very poor mechanical and optical quality. You are better off buying a simple (but well made) telescope. In other words, buy a telescope where the money has gone into basic functionality (good optics and a good mount). Telescopes to be avoided are easily identified, since they come standard with numerous (but often useless) accessories (more on this below)!

### Question 86: 24 September 2012 (Week 39)

Q86: Which Planets are known as Inner Planets?

## Sunday, September 23, 2012

A85: 5 Rings, Neptune's unusual rings are not uniform, but possess bright thick clumps of dust called arcs. The rings are thought to be relatively young and short-lived. Earth-based observations announced in 2005 found that Neptune's rings are apparently far more unstable than previously thought, with some dwindling away rapidly.

## Saturday, September 22, 2012

### My Result: 44,744Km ( Earth's Circumference) using Eratosthenes

Experiment Setup
Data Collection
Calculations

My Result: 44,744Km ( Earth's Circumference)

### Question 85: 22 September 2012 (Week 38)

Q85: What is number of Neptune's ring?

A84: Astronomia Pars Optica is the work of Kepler.

### SpaceX, NASA Target Oct. 7 Launch for First Contracted U.S. Cargo Resupply Mission to Space Statio

NASA managers, Space Exploration Technologies Corp. (SpaceX) officials and international partner representatives Thursday announced Sunday, Oct. 7, as the target launch date for the first contracted cargo resupply flight to the International Space Station under NASA's Commercial Resupply Services (CRS) contract.

Source:NASA

### Orion Spacecraft Makes Virginia Air & Space Center Home

NASA and the Virginia Air & Space Center (VASC) announced today that a full-scale test version of NASA's Orion spacecraft will become part of the center's permanent collection.

The 18,000-pound Orion test vehicle, built at NASA's Langley Research Center in Hampton, Va., was used in the successful Pad Abort-1 test of Orion's launch abort system in May 2010. The abort system is designed to enhance the safety of the crew by providing an escape capability from the launch pad through ascent.

"We are thrilled to become the permanent home for this full-scale test version of NASA's Orion spacecraft," said Brian DeProfio, Interim Director of the VASC. "As the visitor center for NASA's Langley Research Center, this is an ideal way for us to share the NASA story and showcase the latest in NASA technology."

### Hubble Catches Glowing Gas and Dark Dust in a Side-On Spiral

The NASA/ESA Hubble Space Telescope has produced a sharp image of NGC 4634, a spiral galaxy seen exactly side-on. Its disk is slightly warped by ongoing interactions with a nearby galaxy, and it is crisscrossed by clearly defined dust lanes and bright nebulae.

NGC 4634, which lies around 70 million light-years from Earth in the constellation of Coma Berenices, is one of a pair of interacting galaxies. Its neighbor, NGC 4633, lies just outside the upper right corner of the frame, and is visible in wide-field views of the galaxy. While it may be out of sight, it is not out of mind: its subtle effects on NGC 4634 are easy to see to a well-trained eye.

### Curiosity's Stars and Stripes

This view of the American flag medallion on NASA's Mars rover Curiosity was taken by the rover's Mars Hand Lens Imager (MAHLI) during the 44th Martian day, or sol, of Curiosity's work on Mars (Sept. 19, 2012). The flag is one of four "mobility logos" placed on the rover's mobility rocker arms.

### President's Signature On Board Curiosity

This view of Curiosity's deck shows a plaque bearing several signatures of US officials, including that of President Obama and Vice President Biden. The image was taken by the rover's Mars Hand Lens Imager (MAHLI) during the rover's 44th Martian day, or sol, on Mars (Sept. 19, 2012). The plaque is located on the front left side of the rover's deck.

## Friday, September 21, 2012

### Hindustan Aeronautics delivers Mars orbiter mission satellite structure to ISRO

Hindustan Aeronautics Limited has handed over the Mars orbiter mission satellite structure to the ISRO Satellite Centre here.

The mission is aimed at studying the climate, geology, origin and evolution of the red planet, according to the Navratna defence PSU headquartered here.

### Dawn Sees Hydrated Minerals on Giant Asteroid

This perspective view of Marcia crater on the giant asteroid Vesta shows the most spectacularly preserved example of "pitted terrain," an unexpected discovery in data returned by NASA's Dawn mission. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/JHUAPL

NASA's Dawn spacecraft has revealed that the giant asteroid Vesta has its own version of ring around the collar. Two new papers based on observations from the low-altitude mapping orbit of the Dawn mission show that volatile, or easily evaporated materials, have colored Vesta's surface in a broad swath around its equator.

### Roots of Huge Solar Explosions May Lie in 'Coronal Cavities'

The sun's atmosphere dances. Giant columns of solar material – made of gas so hot that many of the electrons have been scorched off the atoms, turning it into a form of magnetized matter we call plasma – leap off the sun's surface, jumping and twisting. Sometimes these prominences of solar material, shoot off, escaping completely into space, other times they fall back down under their own weight.

The faint oval hovering above the upper left limb of the sun in this picture is known as a coronal cavity. NASA’s Solar and Terrestrial Relations Observatory (STEREO) captured this image on Aug. 9, 2007. A team of scientists extensively studied this particular cavity in order to understand more about the structure and magnetic fields in the sun's atmosphere. Credit: NASA/STEREO

The prominences are sometimes also the inner structure of a larger formation, appearing from the side almost as the filament inside a large light bulb. The bright structure around and above that light bulb is called a streamer, and the inside "empty" area is called a coronal prominence cavity.

## Thursday, September 20, 2012

### Question 84: 21 September 2012 (Week 38)

Q84: Whose work is Astronomia Pars Optica?

A83: One Light Year is the distance travel by any object with speed of light for one year.

### The Colliding Spiral Galaxies of Arp 274

Two galaxies are squaring off in Virgo and here are the latest pictures. When two galaxies collide, the stars that compose them usually do not. This is because galaxies are mostly empty space and, however bright, stars only take up only a small fraction of that space. But during the collision, one galaxy can rip the other apart gravitationally, and dust and gas common to both galaxies does collide. If the two galaxies merge, black holes that likely resided in each galaxy center may eventually merge. Because the distances are so large, the whole thing takes place in slow motion -- over hundreds of millions of years. Besides the two large spiral galaxies, a smaller third galaxy is visible on the far left of the above image of Arp 274, also known as NGC 5679. Arp 274 spans about 200,000 light years across and lies about 400 million light years away toward the constellation of Virgo. Credit: NASA, ESA, M. Livio (STScI) and the Hubble Heritage Team (STScI/AURA)

### Potential Habitable Exoplanet Till Date

Four of the Planetary Habitability Laboratory's top six potentially habitable exoplanets have been found since September 2011.
CREDIT: PHL @ UPR Arecibo

### Spot Asteroid Pallas this Week

The bright asteroid Pallas is well placed for observation this week as it reaches opposition in Cetus on Monday September 24.
CREDIT: Starry Night Software
Although we read a lot about asteroids, most amateur astronomers have never seen one. This week, weather permitting, is a great opportunity to view one of the largest and best known space rocks: asteroid Pallas.

### Newfound Alien Planet a Top Contender to Host Life

Artist's rendition of the "super Earth" Gliese 163c, which may be capable of supporting microbial life.
CREDIT: PHL @ UPR Arecibo
A newly discovered alien planet may be one of the top contenders to support life beyond Earth, researchers say.
The newfound world, a "super Earth" called Gliese 163c, lies at the edge of its star's habitable zone — that just-right range of distances where liquid water could exist.

### Space Shuttle Endeavour sits atop NASA's Shuttle Carrier Aircraft

Space shuttle Endeavour sits atop NASA's Shuttle Carrier Aircraft, or SCA, Wednesday, Sept. 19, 2012, at Ellington Field in Houston. Endeavour is making a final trek across the country to the California Science Center in Los Angeles, where it will be permanently displayed. (AP Photo/David J. Phillip)

### Question 83: 20 September 2012 (Week 38)

Q83: What is a Light Year?

### Jake Matijevic' Contact Target for Curiosity

Image credit: NASA/JPL-Caltech
The drive by NASA's Mars rover Curiosity during the mission's 43rd Martian day, or sol, (Sept. 19, 2012) ended with this rock about 8 feet (2.5 meters) in front of the rover. The rock is about 10 inches (25 centimeters) tall and 16 inches (40 centimeters) wide. The rover team has assessed it as a suitable target for the first use of Curiosity's contact instruments on a rock. The image was taken by the left Navigation camera (Navcam) at the end of the drive.

### Curiosity Traverse Map Through Sol 43

Image credit: NASA/JPL-Caltech/Univ. of Arizona

This map shows the route driven by NASA's Mars rover Curiosity through the 43rd Martian day, or sol, of the rover's mission on Mars (Sept. 19, 2012).

The route starts where the rover touched down, a site subsequently named Bradbury Landing. The line extending toward the right (eastward) from Bradbury Landing is the rover's path. Numbering of the dots along the line indicate the distance driven each sol. North is up. The scale bar is 200 meters (656 feet).

### Researchers Brew Up Organics on Ice

Researchers are brewing up icy, organic concoctions in the lab to mimic materials at the edge of our solar system and beyond. The laboratory equipment at NASA's Jet Propulsion Laboratory in Pasadena, Calif., is seen at right, and a very young solar system, with its swirling planet-forming disk, is shown in the artist's concept at left. Image credit: NASA/JPL-Caltech

Would you like icy organics with that? Maybe not in your coffee, but researchers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., are creating concoctions of organics, or carbon-bearing molecules, on ice in the lab, then zapping them with lasers. Their goal: to better understand how life arose on Earth.

### NASA Telescopes Spy Ultra-Distant Galaxy

In the big image at left, the many galaxies of a massive cluster called MACS J1149+2223 dominate the scene. Gravitational lensing by the giant cluster brightened the light from the newfound galaxy, known as MACS 1149-JD, some 15 times. At upper right, a partial zoom-in shows MACS 1149-JD in more detail, and a deeper zoom appears to the lower right.. Image credit: NASA/ESA/STScI/JHU

With the combined power of NASA's Spitzer and Hubble space telescopes, as well as a cosmic magnification effect, astronomers have spotted what could be the most distant galaxy ever seen. Light from the young galaxy captured by the orbiting observatories first shone when our 13.7-billion-year-old universe was just 500 million years old.

### Landing Pads Being Designed for Extraterrestrial Missions

When the Mars Science Laboratory's Curiosity rover landed on Aug. 6, it was another step forward in the effort to eventually send humans to the Red Planet. Using the lessons of the Apollo era and robotic missions to Mars, NASA scientists and engineers are studying the challenges and hazards involved in any extraterrestrial landing.

The technology is known as "vertical takeoff-vertical landing." According to a group working in NASA's Engineering and Technology Directorate at the Kennedy Space Center in Florida, the best approach requires a landing pad already be in place.