Darker Matter: Observation Reveals Anomalous Dark Matter Distributions, Spells Trouble for Cosmologists

The mystery deepens. Scientists have found distribution of dark matter in dwarf galaxies, which is completely anomalous to the current theory of cold dark matter distribution in the Universe. The AMS observation from aboard the ISS has shown that dark matter is spread uniformly throughout the dwarf galaxy, whereas one would expect it to clump around the centre and then thin around towards the edges. This pattern, based on the prediction of the cold dark matter model, is seen in bigger galaxies like our own. Dwarf galaxies provide an exception and no one knows why.

A web of dark matter throughout the Universe?

What really is Dark Matter?

Dark matter refers to the attractive positive density matter that supposedly makes up as much as 23%-26% of the Universe, as compared to the 4% of visible matter (all stars, planets, galaxies everything that we know about!). The rest is dark energy and it is the energy of the vacuum, tending to tear to Universe apart making it accelerate its expansion. Dark matter was proposed by Fritz Zwicky and was initially invoked to explain the high speed of the outer spirals of a galaxy. They were spiraling too fast to be held by gravity of the visible matter. An invisible matter, interacting only through gravity had to be present. Gradually, it was recognized that dark matter could explain other things as well, like the observed cosmic microwave background radiation, unexplained gravitational lensing etc. Matter is believed to reside in the space-time trough created by lumps of dark matter.

It is to explain the motion of such galaxies that dark matter was hypothesized in the first place

The most successful version of dark matter has been the cold dark matter’ model, which says that the dark matter particles, whatever they may be, are moving very slowly with respect to light.

The Study and an Anomaly

The study involved observing the Fornax and Sculptor galaxies, which orbit the Milky Way. These are dwarf galaxies and are thought to be primarily made up of dark matter. What was expected was that the center would be rich in dark matter and then the distribution would thin out towards the edges. What was seen instead, was a uniform distribution, confounding scientists to no end. Matt Walker, the leader for this study conducted by the Harvard-Smithsonian Center for Astrophysics, says

Unless or until theorists can modify that prediction, cold dark matter is inconsistent with our observational data.

Dark matter distributions can be inferred from the motion of stars. The presence of matter curves space and matter particles follow curves on this curved space, called geodesics. The geodesics would be significantly modified by the presence of dark matter. This gives an estimate to the dark matter present. The team investigated the motion of about 2000 stars and found this anomaly.

Matt Walker says

After completing this study, we know less about dark matter than we did before

Well, nature has never been kind, has it?

NASA’s Leap Into Deep Space: Newly Announced Rocket Really Packs A Punch!

NASA’s new generation rocket will be the biggest and baddest rocket ever built. It is the next generation rocket meant for carrying very heavy loads of cargo into space, thanks to a giant booster. It will eventually carry astronauts into space, but that is still a long way away. It is a first step towards NASA’s endeavor for Deep Space Missions.

This announcement by NASA was made yesterday (14th September, 2011).

The Space Launch System, as conceived of by an artist (Courtesy: NASA)

The Space Launch System

The new rocket is called the Space Launch System (SLS) and it will use liquid hydrogen in liquid oxygen as fuel to get the thrust that it intends to achieve.

The entire SLS program is worth at $18 billion, with the rocket alone costing $10 billion. This works out to $3 billion per year for NASA. The rocket will take some time coming, though. The first test flights are expected in faraway 2017.

SLS will use the still use the solid rocket boosters on either side of the SLS core main rocket. The carrying capacity is slated to be 70 metric tons initially, which will eventually touch 130 metric tons with upgrades. As for the amount of thrust, the SLS will deliver about 20 percent more thrust than the Saturn V rockets, which powered the Apollo missions. It will also be taller, at 403 feet, a clear 40 feet taller than the Saturn rockets.

Future bright, present controversial

This is the first concrete announcement of the future plan of progress for NASA after its 30 year Space Shuttle Program ended a couple of months back. In this time, NASA will be using private built rockets to journey to and from the International Space Station and, maybe, even have manned flights.

As with any big project, the SLS was recently embroiled in controversy after the Wall Street Journal published the news that NASA’s estimates for the SLS was nearly $63 billion! The source of this news was found to be a leaked memo and based on hypotheses, rather than facts. The actual costs are of the tune of $20 billion.

The rockets get bigger and bigger, trying to keep up with human ambitions in space.

International Space Station May Need To Go Unmanned For First Time In A Decade

The International Space Station (ISS) may go unmanned in the coming months for the first time in a decade. This is because of the crash of the Russian space vehicle last week. The vehicle was supposed to carry essential supplies to the International Space Station and the astronauts on it.

While there is no dearth of supplies presently, the Russian space agency, Roskosmos, has decided to delay the launch of the next rocket to the ISS. This does put a constraint on the supplies and the astronauts may be asked to descend to earth in November, deserting the ISS. The ISS will then be controlled from the ground via remote control.

Anybody Home? (The ISS)

Of Delays and Remote Controls

Though this is not new, it is a drastic measure. The last time the ISS was unmanned was in 2001. The procedure is present in NASA’s books, but it is a difficult procedure nonetheless. The ISS can be far effectively monitored on-board than from the ground.

Roskosmos gave a sound reason for their decision to delay this present launch, however. They want to check everything thoroughly, so as to prevent a rerun of last week’s embarrassing disaster. Many have started saying that, if the Space Shuttle were in operation, this kind of crisis would never have arisen. Right now, Russian rockets are the only way to get in or out of the Space Station and they are showing glitches. The Soyuz is, however, on standby at the ISS should an emergency arise.

The present crew of three astronauts was supposed to head back to earth on the 8th of September, but even that has been pushed back to 16th. A fresh batch was set to replace them on the 22nd of September, but this launch has been pushed back to early October. Roskosmos and NASA are now thinking whether this launch will be scheduled at all or not.

Meanwhile, the $100 billion floating behemoth silently endures.

Space Mission:Endeavour Lands On Earth For The Last Time

Endeavour has landed. The last space flight, STS-134, of the youngest shuttle in the NASA fleet, beloved by one and all, came to an end after 16 days in space on the second last mission NASA has planned to the International Space Station. Endeavour can now boast of 25 years of space flight career in which it spent 299 days in space, made 4672 orbits of Earth and covered a staggering 122.8 million miles. The shuttle will now be given pride of place at the California Science Center in Los Angelos.

Endeavour Lands at the Kennedy Space Center at 2:35 AM (Courtesy: NASA)

Endeavour’s Journey

Endeavour has been built to replace Challenger after the tragic fate it suffered in 1986. It made its first voyage into space in 1992, on a mission to grab an errant satellite. The darling child of the NASA fleet also had carried astronauts to the Hubble Space Telescope in 1993 in an attempt to correct the alignment of the mirror on the Telescope, after it was found that the much vaunted Space Telescope had blurred vision. The mission was a huge success and Hubble has never had to look back since. Incidentally, Endeavour was also the preferred vessel for the first manned flight undertaken to assemble the International Space Station in 1998.

Endeavour landed at 2:35 AM in the midst of complete darkness and cheered on by ground staff and a handful of people who had gathered at the Kennedy Space Center, Florida. It was an emotional touchdown for all, but especially for Commander Mark Kelly. Kelly’s wife Rep. Gabrielle Giffords is in a rehab center in Houston having suffered a bullet to the head during a mass shooting in Tuscan, Arizona this January. She has since made a miraculous recovery and had in fact attended the Endeavour launch. Kelly has reportedly not called his wife up, since he didn’t want to wake her up so late at night.

What Now?

The emotional scene was slightly buoyed up by the sight of Atlantis being lined up for launch at the launch pad for its last ever flight. Atlantis is due to be launched on the 8th of July tentatively. Discovery, the leader of the fleet, had already been retired in March. It is now housed at the Smithsonian Institution hangar in Washington.

With three out of four shuttles out of operation, NASA is looking for new ones to continue its mission in space. It is also looking at unmanned deep space missions.

Endeavour looks almost too young to retire, but it has done its due. Here’s wishing Endeavour a happy retired life.

Space Mission: NASA Calls Off Endeavour Launch For Minimum Three Days

NASA has just called off the launch of the Space Shuttle Endeavour by at least three days due to a glitch in one of the thermostats onboard ths shuttle. The Kennedy Space Center has issued an explanation why the launch, STS-134, was postponed.

Thermostats are vital to keep the fuel from freezing in space. There are two thermostats on-board the Endeavour. Now, with one of them showing problems, NASA cannot go ahead with just one thermostat, just in case that it too malfunctions. Engineers are not quite sure how this particular thermostat went bust.

Have to wait for another 72 hours before this sight (Courtesy: NASA)

The launch will be no earlier than Monday, 2:33 PM EST (local time for Kennedy Space Center). NASA has already put up a tentative explanation on youtube by Mike Leinbach, the Shuttle Launch Director. You can follow the launch in HD, as it is streamed directly by NASA here.

It is clear that after the disasters of Challenger and Columbia, and with sensitive instruments on-board, NASA would rather embarrass itself and take a step back than go ahead with a risky launch. As Richard Feynman, famous physicist and a panelist on the Challenger investigation panel said about the Challenger disaster in 1986:

Reality must take precedence over public relations, for Nature cannot be fooled.

Hopefully, this delay won’t go beyond Monday.

China Will Build a Manned Space Station In Next 10 Years

China’s venture into space missions is pretty recent, with the first spacewalk taking place just 3 years ago and the history of Chinese astronauts in orbit less than 10 years old. But with a stronger-than-ever economy and a bid to be the next super power, China is taking a bold step. Chinese authorities announced this week their plan to build a manned space station within next 10 years.

Though the name has not been finalized yet, the station may be called Tiangong, meaning “heavenly palace”. The station will weigh 66 tons and would support a crew of three people along with hosting two laboratories for different scientific disciplines including astronomy and biology. The station would have one central module and two science lab modules, with the central module being 60 feet long and the labs around 50 feet each. A part of the preparations, China will send 3 modules in space with the first one being later this year and the last module in 2015.

One of the most interesting observation, however, is the scheduled retiring of ISS (International Space Station) in 2020. If the ISS, sponsored by US, retires as scheduled and the Tiangong goes live as planned, it will be the only manned space station in the orbit. This will give China a great scientific and political advantage over other countries, something which doesn’t usually play well with most developed countries of the world. However, with the long history of space related projects being postponed and even cancelled regularly, we will have to see how this one turns out.

Source PopSci

Space Mission: Endeavour Launch on 29th April, To Carry Anti-Matter Detector Into Space

On the 29th of April, the space shuttle, Endeavour, will liftoff, primarily, to deliver a multi-billion dollar instrument the Alpha Magnetic Spectrometer (AMS) to the International Space Station. The liftoff is scheduled for 1947 GMT  from the Kennedy Space Center, Florida.

The date was fixed after a number of delays, mostly related to quality control measures and safety precautions. Endeavour is expected to spend almost 16 days in orbit, carrying astronauts, who will be doing four scheduled space-walks and various mission activities so that the space station and its instruments operate without shuttle support.

iss
The International Space Station

The Alpha Magnetic Spectrometer:

The device of central importance in this mission is the Alpha Magnetic Spectrometer (AMS), which weighs about 7 tonnes and costs more than US$2 billion. It is designed to detect signs of anti-matter and dark matter. It will inspect cosmic rays – streams of highly energetic charged particles coming from outer space.

The main component of the AMS is the 1900 kg permanent magnet, which can create a magnetic field more than 3000 times stronger than Earth’s. Scientists insisted on a permanent magnet, rather than a superconducting one, since the former lasts longer even though it is weaker.

Nobel Laureate Samuel Ting, principle investigator for the AMS, says:

When we tested the superconducting magnet in a thermal vacuum chamber to simulate space, we found it could only be operated for three years before it needed to get its liquid helium refilled, and there’s really no way to do so without the space shuttle, which has been terminated.

ams
The Alpha Magnetic Spectrometer (Courtesy: NASA)

Why the AMS?

This mission needs to be carried out in space, because the most cosmic rays, being charged particles, interact with the atmospheric atoms and are absorbed. Cosmic rays provide scientists with energy scales that cannot be produced in the lab. A particle accelerator can only go so much high up on the energy scale, but cosmic rays have particles, which have huge energies since they were emitted from unimaginably energetic cosmic events.

Physicists are right now baffled by the questions of baryon asymmetry (why should matter dominate anti-matter, even though the equations don’t suggest that?). The AMS hopes to answer, or at least provide clues to, this and many similar questions; scientists are especially hopeful that it will be able to give some hints about dark matter and its role in the expansion in the Universe. Coincidentally, while the AMS hopes to detect anti-helium nuclei, anti-helium has already been detected on Earth, at RHIC, Brookhaven. (Read here) This detection might help calibrate the AMS with higher precision.

NASA had shelved the AMS project for quite a while due to the Columbia disaster in 2003. However, many scientists were keen to get AMS off the ground and into space. It is an international collaborative effort involving 600 physicists from 16 countries. Further, as Ting puts it,

The idea is that if building the International Space Station cost $100 billion, there should really be a good science project there.

Here’s wishing NASA and the Endeavour team the very best for this space mission.