Tag Archives: Space

Early Earth Might Have Had Two Moons, Which Collided To Form One

Imagine that the full moon night had two moons instead of one, making it doubly romantic! If you could somehow magically survive in the volcanic early Earth, then you would have been able to play the perfect Romeo. Scientists think that the early Earth had two moons, which collided and fused to make the one that we see today.

This startling new revelation comes from the fact that the two sides of the moon the one facing us and the dark side have very different landscapes. The dark side is so called because we just cannot see it, even though it is just as lit as the visible side.

Lunar Apocalypse?

The tell-tale marks, or lack of them

The visible side has flat expansive plains, called maria’ (meaning sea’ in Latin), while the far side is mountainous, with mountains as high as 2 km. Simulations, trying to explain this discrepancy, now point to the earlier presence of a second moon, which might have slammed into the larger one, producing the maria and giving the features of the moon we see today. This is further backed up by known observations that the lunar crust on the near side has more phosphorus and radioactive elements of potassium (the radioactive isotope), uranium and thorium. On the far side, as far as we know, they do not occur or are deeply embedded in the surface. This can be explained by noting that impact could have melted a part of the near side, allowing for hidden elements to rise to the surface. The companion body is calculated to have been just 4% as massive as the bigger moon and about 750 miles across.

The Simulation done, which shows the collision (Credit: Asphaug and Martin Jutzi, Bern University, Switzerland)

The stability of the companion body: why it crashed into the bigger moon

There is also another explanation that is required: why the companion moon crashed into its larger partner. Asked to a physicist, this implies a stability problem and the underlying question involved asking about why instability crept into the system. There are points in the space around any celestial body orbiting another celestial body, where the gravitational attractions of the two bodies cancel each other out. These points are stable points and are known as Lagrangian points’. There are two Lagrangian points in the current Earth-Moon system, one just in front of the moon and one just behind it. It is conjectured (and can be calculated via lengthy calculations using Newton’s gravity law) that the early Earth-two Moon system also had Lagrangian points just in front and behind the bigger moon. The companion moon would’ve nested itself in and around that Lagrangian point. When the moon moved away from the Earth (which is still happening due to the presence of tidal forces), the stable Lagrangian points also shifted. This led to the destabilizing of the orbit of the smaller moon, which then crashed into the nearby large body.

Explaining the dark side of the moon

Even though slightly off-topic, it is worth mentioning that the equality of the periods of orbital and axial spins of the moon is due to the energy loss mechanism due to tides. The most efficient way to distribute energy in the Earth-Moon system, given that the energy dissipation from the entire system is miniscule, is by having the period of the moon around the Earth and on its own axis as identically same. This, remember, leads to the dark side phenomenon. The enigmatic dark side, which has even inspired great music (Pink Floyd, anyone?),  is closely related to tides.

Asphaug and Martin Jutzi of University of Bern, Switzerland, who are responsible for coming up with the calculations and simulations, published their findings in the August 4 issue of Nature.

Scientists Find Oxygen Gas In Deep Space

Though we still won’t be able to refill our oxygen tanks in outer space at this moment, the discovery of molecular oxygen gas is still momentous. Scientists have discovered molecular oxygen gas in the famous Orion Nebula (not constellation), which is about 1500 light years away from us.

The Orion Nebula in all its beauty

The excitement surrounding this discovery stems from the fact that even though atomic oxygen (i.e. individual oxygen atoms) are found, molecular oxygen (i.e. molecules of oxygen) has never been found till now. The history of this search is long and stretches back 230 years.

What’s the difference?

Molecular oxygen is made up of two atoms of oxygen, which are bound together. On Earth, atomic oxygen is hardly found in the atmosphere and most of it lies in the ozone layer. This is because, in absence of energetic ionising radiation like UV rays, one atom of oxygen always tends to bond with another atom of oxygen and attain a state of lower energy, giving rise to the oxygen molecule, which is more stable than the oxygen in the atomic form. But conditions in space are different. Ionising radiations flood the inter-stellar medium.

The elements

Oxygen, being the third most abundant element in the Universe, after Hydrogen and Helium, occurs, surprisingly, in predominantly atomic form. Hydrogen fills up 98% of the total elemental mass of the Universe, followed by Helium at roughly 1.9%. The rest 0.1% is contributed by all other elements in the cosmos.

Discovery and the principle behind it

This discovery is credited to the European Space Agency’s Hershel Space Observatory. Actually, the Swedish telescope, Odin, has spotted signatures of molecular oxygen (by looking at the colour/frequency of the radiated light) in 2007. Hershel has confirmed that discovery using its infrared detectors.

All elements leave radiate light of some specific frequency when excited. The radiation frequency is the signature of an element, much like fingerprint is an identity of a person. Even molecules have radiation spectrum, which distinguishes it uniquely. Atomic and molecular oxygen has different patterns of radiation and, by studying the peaks (highs) and troughs (lows or valleys) in the spectrum, scientists can confirm the presence of the element with absolute certainty. This has been the greatest achievement of spectroscopy.

The Spectral lines of oxygen

As is usual in science, any discovery opens up new questions and this is no different. Scientists can now look into the question of why molecular oxygen occurs in certain cosmic pockets, while atomic oxygen is so widespread. Also note that the presence of molecular oxygen doesn’t say anything about the existence of life.

The charm of Orion never seems to fade.

Private Player, SpaceX, Plans To Dock With The International Space Station Later This Year

The future of American contribution in space seems to lie in the hands of private space companies. A private aerospace company, focusing on space flight, Space Exploration (or SpaceX) has been approved by NASA to send its Dragon spacecraft to the International Space Station on an unmanned flight, scheduled sometime in late November and attempt a docking with the ISS in early December this year.

NASA has been relying heavily on private space vehicles to take up the mantle of ferrying hardware reliably to the International Space Station from its own space shuttle program. So much so that NASA has even been bottle-feeding them with cash  in order to help them grow. Even manned flight is now in the cards, but not in the near future.

Plans

SpaceX will attempt to fly its Dragon Space Capsule past the ISS as its first mission target on November 30th and then attempt a docking with the ISS on the 9th of December this year. SpaceX and NASA are both contemplating a combination of the two missions into one, which will involve a brief fly-by before a docking attempt.

The Dragon Cargo Ship made by SpaceX (Photo: SpaceX)

The four decade old Space Shuttle Program came to an end on the 21st of July this year after Atlantis landed and, since then, NASA has been looking at private players. SpaceX is a leader in this against three more players. As per revealed details of its contract with NASA, SpaceX will charge $1.6 billion for 12 cargo deliveries, making it $133 million per flight. This is tiny compared to the expenditure of more than $1 billion per flight of the space shuttle.

The Bigger Question(s)

If the Dragon cargo ship is delivered properly, using the Falcon rockets (made by SpaceX itself), it will be a dramatic vindication of NASA’s faith in private players in the wake of the end of the space shuttle program. The Falcon rocket parts are already assembled at the Cape Canaveral launch site. The Dragon spacecraft is yet to arrive and is expected in August or September.

The Falcon rocket

The wide space left behind by the end of the space shuttle program leaves room for the super-reliable Soyuz to become the primary player in the space game. Roskosmos, the Russian space agency, realizes as much:

From today, the era of the Soyuz has started in manned space flight, the era of reliability

SpaceX is the not the only player in the game. Following it, but not very close behind, is Orbital Sciences Corp., which also has landed a NASA contract. It is planning its Cygnus’ ship for a February 2012 launch.

Reliability is a key question on everyone’s mind. If that is answered in the positive, there will be inevitable questions on the ethical decision to let private players enter into virgin territory, especially when manned space flight will be involved.

NASA’s Jupiter Mission Satellite to be Launched On August 5; Deep Space Missions to Follow

NASA is all set to launch the spacecraft Juno for its Jupiter mission, using the powerful Atlas V 551 rocket as the launch vehicle. The scheduled launch date is August 5 from Cape Canaveral, Florida.

Mission Juno is a decade old project of NASA designed to get information about the Jupiter. It comprises the Juno satellite, which is worth $1.1 billion. The launch vehicle is one of the most powerful launch vehicles in the world. It was originally built as an intercontinental ballistic missile (Atlas Missile).

The Juno Satellite

Named After A Goddess

The name of the mission comes from the Roman mythological figure, Juno, who is the daughter of the Roman god Saturn and the sister, and also wife, of the chief Roman god, Jupiter. She’s also the mother of Mars and Vulcan. Scientists hope that Jupiter will finally share some of its wonderful secrets with a spacecraft, which is His wife’s namesake.

What about Jupiter and the mission

Jupiter is a remarkable planet. It is the closest to a star and is thought to be the remnants of a second star after the Sun, which never materialised. Jupiter is the only planet known, which has its own energy source, much like the Sun, but dimmer. It was often called a Brown Star’, but that tag has been shed as Jupiter is believed to have formed as a planet forms. It has a mass which is about a thousandth of a Solar Mass, which is too less for it to be able to fuse hydrogen. The debate is still out as to whether Jupiter is a failed star or a Superplanet.

Artist's impression of Juno flying to Jupiter

NASA scientists are primarily interested in the composition of the gas giant. Scott Bolton, the principal investigator for the Juno mission, put it most pithily:

It got the majority of the leftovers after the sun formed. We want the ingredient list.

Juno will orbit the Sun for two years, close to the Earth’s orbit, before using the Earth’s gravity as a slingshot to shoot itself farther out. It is expected to reach Jupiter by 2016. Juno will draw power from the three solar panels provided on it, in contrast to the use of nuclear power for Galileo and Voyager.

The path to be taken by Juno

The mission hopes to know more about what lies beneath the surface of Jupiter, especially the core. Juno is also expected to be the pioneer for more deep space missions, especially after the Space Shuttle Program expired a few days back.

As the date nears, we will bring you the exact time of the launch and more relevant details. Bookmark this site for more.

Discovered: A Super Massive Black Hole Weighing As Much As Two Billion Suns

This is a big astrophysical find, literally big! The Chandra X-Ray telescope has detected the signature of a supermassive black hole by observing the hot gases falling into it. The estimated mass of the black hole is a huge 2 Billion times the mass of the Sun!

The compact object lies at the heart of the galaxy known as NGC 3115, located at a distance of 32 million light-years away from Earth, making this the closest billion-solar-mass object to Earth. Astronomers have long been interested in the activity in this region, especially the gas falling into the central object. There have been various observations in the various frequencies, but this is only the first time when the X-Ray signatures have been clearly observed. The Chandra data suggests a huge mass for the black hole, given the temperature of the glowing gas falling into it. Only if the gas glows extremely intensely, does it give off X-Rays. NGC 3115 is about a million times brighter in X-Rays than in visible light.

How They Found Out the Mass

There is a term, called Bondi radius, named after the astrophysicist Hermann Bondi, which describes how the gas is affected by the black hole gravity. It is defined as the distance at which the gravity first starts dominating the random kinetic motion of the gas and the gas starts spiraling into the black hole.

The NGC 3115 galaxy

The data from the Chandra telescope suggests that the Bondi Radius is 700 light years away from the black hole!! In comparison, the closest star to Earth, after the Sun, is about 4 light years away. This gives an estimate of the mass of the black hole and the calculation suggests 2 billion solar masses!!

Any Use?

This finding is not only one for public consumption, but also scientific fodder. It may help to explain how matter flows into a black hole, as a tremendous amount of data is available due to the luminosity of the black hole.

It also brings up questions. Scientists still don’t know how such extremely massive black holes stay dim. As Dr. Jimmy Irwin, assistant professor of University of Alabama’s Physics Department says:

A leading mystery in astrophysics is how the area around massive black holes can stay so dim, when there’s so much fuel available to light up.

It is often said that astronomy is a humbling science. This just confirms that saying.

Discovered: A Small Asteroid Which Shares Orbit With Earth

A tiny asteroid, having roughly the same orbit as the Earth, has been discovered. The companion asteroid is about 300 yards across. It leads the Earth as both the objects orbit the Sun. However, the asteroid has variable speed and a more eccentric orbit, often leading the Earth by as much as half-an-orbit.

The finding is due to work by Martin Connors of Canada’s Athabasca University and his colleagues. The findings have been published in the journal Nature.

The new object

The asteroid has been named 2010 TK7, and was discovered last year by NASA’s WISE satellite. This is the first time such a companion rocky body has been discovered to share the orbit with Earth. Many such bodies are known to either share the orbit with Jupiter or Saturn or become their moons. In fact, the fate of many objects sharing orbits with such large planets is that they eventually become satellites.

Asteroids are giant rocks in space, orbiting the Sun, believed to be remnants of the planet forming era. These are leftovers, those chunks which did not form planets. Among the big asteroids in the Solar System is Ceres, which has its own orbit between Mars and Jupiter. It is believed to be remnants of a planet which broke up, probably after being struck by a large comet.

Earth is not alone

Rocky bodies which share an orbit with a planet are called Trojans’. This object 2010 TK7 is the first Trojan found for Earth. Jupiter is known to have about 5000 Trojans, rocks brought to it by its intense gravitational pull. Mars, Neptune and Saturn also have their share, though the number is much less than that of Jupiter.

Trojans around Jupiter (green dots)

There is no fear of an asteroid crashing onto the Earth in the immediate future. It’s just a harmless body accompanying the Earth on its annual journey around the Sun.

NASA’s Next Mars Rover Landing Site Now Confirmed to be Gale Crater

It’s official. The New Mars Rover, Curiosity, will land in the Gale Crater.

We had earlier reported the narrowing down of the possible landing sites of the Mars Rover to just two here. We also reported that unofficial news suggests that the finalised landing spot will be Gale Crater and not Eberswalde Crater. Now, we stand officially vindicated. The announcement was made today i.e. on 22nd July, 2011.

The map of the landing site

The Gale Crater is a 96 mile wide crater, chosen since it is thought to harbor signs of old water flows. If Mars can support microbial life, this would be the place to find it.

Curiosity will be the largest and the most expensive Mars Rover ever sent. It weighs a ton and costs $2.6 billion. The tentative launch date is 25 November, but that is yet to be confirmed officially.

The Curiosity rover is being seen as a precursor of manned missions to Mars, something that NASA has never attempted during the Space Shuttle Program days. Now that the Space Shuttle Program is over, it aims to concentrate more on deep space exploration, rather than the International Space Station.

Curiosity will be gently airdropped into the Gale Crater, rather than the airbag cushioned freefall release method used in the case of Spirit and Opportunity, the previous Mars Rovers.

We hope to soon know more about the planet that has enthralled humanity for so long. Watch this space for more…

Final Landing Of Atlantis on Thursday; Is SpaceX The New Option After NASA’s Space Shuttle Program? [Updated]

With Atlantis landing tomorrow, i.e. the 19th of July, 2011, the space shuttle program comes to an end. This is really the final hurrah!

NASA has cleared STS-135 for the landing tomorrow. Today, NASA mission managers performed a last minute inspection of the vital components of the space shuttle, including the all-important heat shield. No one would want a re-run of Columbia and NASA found that the heat resistant tiles were all in good condition. The space shuttle will return to Earth after a 12-day mission, during which it provided last touches to the International Space Station. The landing is expected to be at 5:56 AM EST or 9:56 AM GMT at the Kennedy Space Center, Cape Canaveral, Florida. Atlantis launched on 8th July, 2011.

Weather seems to favour NASA as there are no forecasts of cloudy skies or rain. Should Atlantis miss this window, due to rain or other unforeseen factors, it will have another chance during a second window, which will open up at 7:32 AM EST. The options do not end there Atlantis will even be able to land on Friday, should it not be able to do so on Thursday.

Atlantis Launch (Photo: NASA)

The question on everyone’s mind is this: What next? NASA will have no rockets to put astronauts in space for a while now. During the years 2014 2016, it will hitch rides on Russian rockets as part of a $763 million contract. There are 12 flights planned in the agreement.

NASA hopes that it will gain a space shuttle capable of carrying a crew by the end of 2016, thanks to one of the four private companies that NASA’s been bottle-feeding with cash. Of the four, SpaceX (or Space Exploration Technologies) leads the pack followed by others like Blue Origin, the Boeing Company and the Sierra Nevada Corporation.

The SpaceX arsenal

SpaceX has already demonstrated its capability with numerous successful test-flights of the Falcon-9 rocket, which it has built. It has also launched its own space capsule, called Dragon, from the Kennedy Space Center.

This seems to be the future, as the sun sets on one of the most ambitious projects in human history. Rosy picture? Only time will tell.

Update:

Atlantis, STS-135, lands for the last time!

Atlantis landed without a hitch during the first window itself right on time at 5:57 AM (EST) at the Kennedy Space Center. This ends the majestic space shuttle program.

Hubble Discovers a Fourth New Moon of Pluto

Hubble has done it again. It has captured a hitherto unknown fourth moon of Pluto, the dwarf planet. The three known moons of Pluto are Charon, Nix and Hydra. The fourth one, discovered just recently on 3rd July, 2011, and officially announced today by NASA and SETI, is temporarily known as P4.

Pluto was stripped of its planet tag on 24th August, 2006 and was relegated to the status of dwarf planet’ along with Eris and Ceres. Eris is, in fact, more massive than Pluto.

An animation showing Pluto. Done using images from Hubble (Photo: NASA)

Charon is the most well-known moon of Pluto and was the only moon discovered till 2005. It is quite large, with a size comparable with Pluto. In 2005, two newer moons were discovered and named Nix and Hydra. It is not known whether this recently discovered moon, P4, was there at the time of the discovery of the previous moons or was captured more recently.

The photo captured by Hubble. (Courtesy: SETI/NASA)

It was due to the wonder called the Hubble Space Telescope that a cold object, tiny in size and moving fast around a very distant body could be photographed. Mark Showalter of SETI Institute in Mountain View, California has this to say:

I find it remarkable that Hubble’s cameras enabled us to see such a tiny object so clearly from a distance of more than 3 billion miles (5 billion km).

The diameter of the new moon is just 8-21 miles, while Charon, by comparison, is a giant at 648 miles. Nix and Hydra are both about 50 miles in diameter.

NASA aims to discover more about the body least known to man with the upcoming New Horizons mission. New Horizons will hope to fly past Pluto in 2015, using inputs from Hubble’s photos to chart out its path.

NASA’s Mars Rover’s Landing Destination Soon To Be Decided; Final Announcement on Friday

The next Mars Rover finally knows where to go well, almost knows. NASA has narrowed down the shortlisted sites to just two the Eberswalde Crater or the Gale Crater.

The two proposed landing site. Colors show elevation. (Image: NASA)

Curiosity, the name of NASA’s Mars Rover, will be launched at either of these sites. NASA will make the final destination official on Friday, i.e. the 22nd of July. Of the two, NASA administrators have apparently chosen Gale Crater’, but this report is unconfirmed as yet. Curiosity is currently housed at the Smithsonian Institute’s National Air and Space Museum. The launch is scheduled, as of now, on 25th November, 2011.

The Curiosity Rover at the Smithsonian Institute National Air and Space Museum (Photo Courtesy: NASA)

Following in illustrious footsteps

Curiosity is following in the footsteps of the triumphant rovers Opportunity and Spirit. It will follow up what these earlier rovers found. It will land in a radical new fashion. Whereas Spirit and Opportunity landed on Mars sitting atop airbags after being airdropped, Curiosity will land gently, guided by a Sky Crane with no need for airbags.

An artist's impression of the landing of the Mars Rover

Packing high-end scientific equipments such as a laser-induced breakdown spectroscopy system, as part of the ChemCam suite, a Sample Analyser (SAM), X-Ray diffraction instruments and radiation detectors, Curiosity is expected to tell us about composition of the Mars soil and any sign of organic matter. A primary concern in scientific circles is to find the precise surface temperature along with its diurnal variation, the exact composition in terms of percentage of elements like carbon, nitrogen, hydrogen etc. and get better photographs of the surface.

Mars: the mystery

Mars has always been held as an enigmatic place, with the ancients even treating it as a God of War. Given the previous rover missions, we now know better! Unfortunately, there are a lot of false stories about the planet as well. There are no water carrying canals in Mars. The Italian word canallae’ got mistranslated as canals’, instead of the more appropriate channels’. Canals conjure up a human or unnatural construct, thus leading to the wide spread speculation of the existence of life on Mars. There have been so signs of any life, leave alone a form intelligent enough to build an irrigation system. Ridges and other signs of abrasion do suggest the earlier existence of flowing water, but even that has not been confirmed. Many are interested to know whether the Red Planet might have anything equivalent to a water table.

Curiosity has always yielded a lot for the human race. Let’s just hope that the literal namesake will carry on that process forward.