Tag Archives: moon

Science, politics, news agenda and our priorities

By Syed Faisal ur Rahman


 

Recent postponement of the first Organization of Islamic Countries (OIC) summit on Science and Technology and COMSTECH 15th general assembly meeting, by the government of Pakistan due to security reasons tells a lot about our national priorities.

The summit was first of its kind meeting of the heads of state and dignitaries from the Muslim world on the issue of science and technology.

Today most Muslim countries are known in other parts of the world as backward, narrow minded and violent regions. Recent wars in the Middle East, sectarian rifts and totalitarian regimes are also not presenting a great picture either. While rest of the world is sending probes towards the edge of our solar system, sending missions to Mars and exploring moons of Saturn, we are busy and failing in finding moon on the right dates of the Islamic calendar.

Any average person can figure out that we need something drastic to change this situation. This summit was exactly the kind of step we needed for a jump start. Some serious efforts were made by the COMSTECH staff under the leadership of Dr. Shaukat Hameed Khan and even the secretary general of OIC was pushing hard for the summit. According to reports, OIC secretary general personally visited more than a dozen OIC member countries to successfully convince their head of states to attend the summit.

This summit would have also provided an opportunity to bring harmony and peace in the Muslim world as many Muslim countries are at odds with each other on regional issues like in Syria, Iraq, Yemen and Afghanistan.

Last century saw enormous developments in the fields of fundamental science, which also helped countries to rapidly develop their potential in industry, medical sciences, defense, space and many other sectors. Countries which made science and technology research and education as priority areas emerged as stronger nations as compared to those who merely relied on agriculture and the abundance of natural resources. We are now living in an era where humanity is reaching to the end points of our solar system through probes like Voyager 1, sent decades ago by NASA with messages from our civilization; Quantum computing is well on its way to become a reality; Humanity is also endeavoring to colonize other planets through multi-national projects; We are also looking deepest into the space for new stars, galaxies and even to some of the earliest times after the creation of our universe through cosmic microwave background probes like Planck.

Unfortunately, in Pakistan, anti-science and anti-research attitudes are getting stronger. The lack of anti-science and anti-research attitude is not just limited to the religious zealots but the so called liberals of Pakistan do not simply put much heed to what is going around in the world of science.

If you are one of the regular followers of political arena, daily news coverage on the media and keep your ears open to hear what is going around in the country then you can easily get the idea what are our priorities as a nation. How many talk shows we saw on the main stream media over the cancellation of the summit? How many questions were raised in the parliament?

The absence or very unnoticeable presence of such issues is conspicuous and apart from one senator, Senator Sehar Kamran, who wrote a piece in a news paper, no politician even bothered to raise the relevant questions.

Forget about main stream media or politicians. If we go to social media or drawing room discussions, did you hear anyone discussing the issue in a debate when we make  fuss about issues like what kind of dress some xyz model was wearing on her court hearing in a money laundering case or which politician’s marriage is supposedly in trouble or whose hand Junaid Jamshed was holding in group photo?

We boast about our success in reducing terrorism through successful military operations and use that success to attract investors, sports teams and tourists but on the other hand we are using security concerns as an excuse to cancel an important summit on the development of science and technology. This shows that either we are confused or hypocrites or we are simply not ready for any kind of intellectual growth.

There is a need to seriously do some brain storming and soul searching about our priorities.  One thing which I have learned as a student of Astronomy is that we are insignificant as compared to the vastness of our universe, the only thing which can make us somewhat special as compared to other species on earth or a lifeless rock on Pluto is that we can challenge our thinking ability to learn, to explore and to discover. Unfortunately, in our country we are losing this special capacity day by day.

For the first time, spacecraft catch a solar shockwave in the act

Solar storm found to produce “ultrarelativistic, killer electrons” in 60 seconds.

By Jennifer Chu


CAMBRIDGE, Mass. – On Oct. 8, 2013, an explosion on the sun’s surface sent a supersonic blast wave of solar wind out into space. This shockwave tore past Mercury and Venus, blitzing by the moon before streaming toward Earth. The shockwave struck a massive blow to the Earth’s magnetic field, setting off a magnetized sound pulse around the planet.

NASA’s Van Allen Probes, twin spacecraft orbiting within the radiation belts deep inside the Earth’s magnetic field, captured the effects of the solar shockwave just before and after it struck.

Now scientists at MIT’s Haystack Observatory, the University of Colorado, and elsewhere have analyzed the probes’ data, and observed a sudden and dramatic effect in the shockwave’s aftermath: The resulting magnetosonic pulse, lasting just 60 seconds, reverberated through the Earth’s radiation belts, accelerating certain particles to ultrahigh energies.

“These are very lightweight particles, but they are ultrarelativistic, killer electrons — electrons that can go right through a satellite,” says John Foster, associate director of MIT’s Haystack Observatory. “These particles are accelerated, and their number goes up by a factor of 10, in just one minute. We were able to see this entire process taking place, and it’s exciting: We see something that, in terms of the radiation belt, is really quick.”

The findings represent the first time the effects of a solar shockwave on Earth’s radiation belts have been observed in detail from beginning to end. Foster and his colleagues have published their results in the Journal of Geophysical Research.

Catching a shockwave in the act

Since August 2012, the Van Allen Probes have been orbiting within the Van Allen radiation belts. The probes’ mission is to help characterize the extreme environment within the radiation belts, so as to design more resilient spacecraft and satellites.

One question the mission seeks to answer is how the radiation belts give rise to ultrarelativistic electrons — particles that streak around the Earth at 1,000 kilometers per second, circling the planet in just five minutes. These high-speed particles can bombard satellites and spacecraft, causing irreparable damage to onboard electronics.

The two Van Allen probes maintain the same orbit around the Earth, with one probe following an hour behind the other. On Oct. 8, 2013, the first probe was in just the right position, facing the sun, to observe the radiation belts just before the shockwave struck the Earth’s magnetic field. The second probe, catching up to the same position an hour later, recorded the shockwave’s aftermath.

Dealing a “sledgehammer blow”

Foster and his colleagues analyzed the probes’ data, and laid out the following sequence of events: As the solar shockwave made impact, according to Foster, it struck “a sledgehammer blow” to the protective barrier of the Earth’s magnetic field. But instead of breaking through this barrier, the shockwave effectively bounced away, generating a wave in the opposite direction, in the form of a magnetosonic pulse — a powerful, magnetized sound wave that propagated to the far side of the Earth within a matter of minutes.

In that time, the researchers observed that the magnetosonic pulse swept up certain lower-energy particles. The electric field within the pulse accelerated these particles to energies of 3 to 4 million electronvolts, creating 10 times the number of ultrarelativistic electrons that previously existed.

Taking a closer look at the data, the researchers were able to identify the mechanism by which certain particles in the radiation belts were accelerated. As it turns out, if particles’ velocities as they circle the Earth match that of the magnetosonic pulse, they are deemed “drift resonant,” and are more likely to gain energy from the pulse as it speeds through the radiation belts. The longer a particle interacts with the pulse, the more it is accelerated, giving rise to an extremely high-energy particle.

Foster says solar shockwaves can impact Earth’s radiation belts a couple of times each month. The event in 2013 was a relatively minor one.

“This was a relatively small shock. We know they can be much, much bigger,” Foster says. “Interactions between solar activity and Earth’s magnetosphere can create the radiation belt in a number of ways, some of which can take months, others days. The shock process takes seconds to minutes. This could be the tip of the iceberg in how we understand radiation-belt physics.”

Source: MIT News

Timeline of the approach and departure phases — surrounding close approach on July 14, 2015 — of the New Horizons Pluto encounter.
Image Credit: NASA/JHU APL/SwRI

NASA’s New Horizons Spacecraft Begins First Stages of Pluto Encounter

NASA’s New Horizons spacecraft recently began its long-awaited, historic encounter with Pluto. The spacecraft is entering the first of several approach phases that culminate July 14 with the first close-up flyby of the dwarf planet, 4.67 billion miles (7.5 billion kilometers) from Earth.

“NASA first mission to distant Pluto will also be humankind’s first close up view of this cold, unexplored world in our solar system,” said Jim Green, director of NASA’s Planetary Science Division at the agency’s Headquarters in Washington. “The New Horizons team worked very hard to prepare for this first phase, and they did it flawlessly.”

The fastest spacecraft when it was launched, New Horizons lifted off in January 2006. It awoke from its final hibernation period last month after a voyage of more than 3 billion miles, and will soon pass close to Pluto, inside the orbits of its five known moons. In preparation for the close encounter, the mission’s science, engineering and spacecraft operations teams configured the piano-sized probe for distant observations of the Pluto system that start Sunday, Jan. 25 with a long-range photo shoot.

 

 

Timeline of the approach and departure phases — surrounding close approach on July 14, 2015 — of the New Horizons Pluto encounter. Image Credit: NASA/JHU APL/SwRI
Timeline of the approach and departure phases — surrounding close approach on July 14, 2015 — of the New Horizons Pluto encounter.
Image Credit: NASA/JHU APL/SwRI

The images captured by New Horizons’ telescopic Long-Range Reconnaissance Imager (LORRI) will give mission scientists a continually improving look at the dynamics of Pluto’s moons. The images also will play a critical role in navigating the spacecraft as it covers the remaining 135 million miles (220 million kilometers) to Pluto.

“We’ve completed the longest journey any spacecraft has flown from Earth to reach its primary target, and we are ready to begin exploring,” said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.

LORRI will take hundreds of pictures of Pluto over the next few months to refine current estimates of the distance between the spacecraft and the dwarf planet. Though the Pluto system will resemble little more than bright dots in the camera’s view until May, mission navigators will use the data to design course-correction maneuvers to aim the spacecraft toward its target point this summer. The first such maneuver could occur as early as March.

“We need to refine our knowledge of where Pluto will be when New Horizons flies past it,” said Mark Holdridge, New Horizons encounter mission manager at Johns Hopkins University’s Applied Physics Laboratory (APL) in Laurel, Maryland. “The flyby timing also has to be exact, because the computer commands that will orient the spacecraft and point the science instruments are based on precisely knowing the time we pass Pluto – which these images will help us determine.”

The “optical navigation” campaign that begins this month marks the first time pictures from New Horizons will be used to help pinpoint Pluto’s location.

Throughout the first approach phase, which runs until spring, New Horizons will conduct a significant amount of additional science. Spacecraft instruments will gather continuous data on the interplanetary environment where the planetary system orbits, including measurements of the high-energy particles streaming from the sun and dust-particle concentrations in the inner reaches of the Kuiper Belt. In addition to Pluto, this area, the unexplored outer region of the solar system, potentially includes thousands of similar icy, rocky small planets.

More intensive studies of Pluto begin in the spring, when the cameras and spectrometers aboard New Horizons will be able to provide image resolutions higher than the most powerful telescopes on Earth. Eventually, the spacecraft will obtain images good enough to map Pluto and its moons more accurately than achieved by previous planetary reconnaissance missions.

APL manages the New Horizons mission for NASA’s Science Mission Directorate in Washington. Alan Stern, of the Southwest Research Institute (SwRI), headquartered in San Antonio, is the principal investigator and leads the mission. SwRI leads the science team, payload operations, and encounter science planning. New Horizons is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. APL designed, built and operates the spacecraft.

For more information about the New Horizons mission, visit:

www.nasa.gov/newhorizons

Losing air |New study finds a barrage of small impacts likely erased much of the Earth’s primordial atmosphere.

By Jennifer  Chu


CAMBRIDGE, MA — Today’s atmosphere likely bears little trace of its primordial self: Geochemical evidence suggests that Earth’s atmosphere may have been completely obliterated at least twice since its formation more than 4 billion years ago. However, it’s unclear what interplanetary forces could have driven such a dramatic loss.

Now researchers at MIT, Hebrew University, and Caltech have landed on a likely scenario: A relentless blitz of small space rocks, or planetesimals, may have bombarded Earth around the time the moon was formed, kicking up clouds of gas with enough force to permanently eject small portions of the atmosphere into space.

Tens of thousands of such small impacts, the researchers calculate, could efficiently jettison Earth’s entire primordial atmosphere. Such impacts may have also blasted other planets, and even peeled away the atmospheres of Venus and Mars.

In fact, the researchers found that small planetesimals may be much more effective than giant impactors in driving atmospheric loss. Based on their calculations, it would take a giant impact — almost as massive as the Earth slamming into itself — to disperse most of the atmosphere. But taken together, many small impacts would have the same effect, at a tiny fraction of the mass.

Hilke Schlichting, an assistant professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences, says understanding the drivers of Earth’s ancient atmosphere may help scientists to identify the early planetary conditions that encouraged life to form.

“[This finding] sets a very different initial condition for what the early Earth’s atmosphere was most likely like,” Schlichting says. “It gives us a new starting point for trying to understand what was the composition of the atmosphere, and what were the conditions for developing life.”

Schlichting and her colleagues have published their results in the journal Icarus.

Efficient ejection

The group examined how much atmosphere was retained and lost following impacts with giant, Mars-sized and larger bodies and with smaller impactors measuring 25 kilometers or less — space rocks equivalent to those whizzing around the asteroid belt today.

The team performed numerical analyses, calculating the force generated by a given impacting mass at a certain velocity, and the resulting loss of atmospheric gases. A collision with an impactor as massive as Mars, the researchers found, would generate a shockwave through the Earth’s interior, setting off significant ground motion — similar to simultaneous giant earthquakes around the planet — whose force would ripple out into the atmosphere, a process that could potentially eject a significant fraction, if not all, of the planet’s atmosphere.

However, if such a giant collision occurred, it should also melt everything within the planet, turning its interior into a homogenous slurry. Given the diversity of noble gases like helium-3 deep inside the Earth today, the researchers concluded that it is unlikely that such a giant, core-melting impact occurred.

Instead, the team calculated the effects of much smaller impactors on Earth’s atmosphere. Such space rocks, upon impact, would generate an explosion of sorts, releasing a plume of debris and gas. The largest of these impactors would be forceful enough to eject all gas from the atmosphere immediately above the impact’s tangent plane — the line perpendicular to the impactor’s trajectory. Only a fraction of this atmosphere would be lost following smaller impacts.

To completely eject all of Earth’s atmosphere, the team estimated, the planet would need to have been bombarded by tens of thousands of small impactors — a scenario that likely did occur 4.5 billion years ago, during a time when the moon was formed. This period was one of galactic chaos, as hundreds of thousands of space rocks whirled around the solar system, frequently colliding to form the planets, the moon, and other bodies.

“For sure, we did have all these smaller impactors back then,” Schlichting says. “One small impact cannot get rid of most of the atmosphere, but collectively, they’re much more efficient than giant impacts, and could easily eject all the Earth’s atmosphere.”

Runaway effect

However, Schlichting realized that the sum effect of small impacts may be too efficient at driving atmospheric loss. Other scientists have measured the atmospheric composition of Earth compared with Venus and Mars. These measurements have revealed that while each planetary atmosphere has similar patterns of noble gas abundance, the budget for Venus is similar to that of chondrites — stony meteorites that are primordial leftovers of the early solar system. Compared with Venus, Earth’s noble gas budget has been depleted 100-fold.

Schlichting realized that if both planets were exposed to the same blitz of small impactors, Venus’ atmosphere should have been similarly depleted. She and her colleagues went back over the small-impactor scenario, examining the effects of atmospheric loss in more detail, to try and account for the difference between the two planets’ atmospheres.

Based on further calculations, the team identified an interesting effect: Once half a planet’s atmosphere has been lost, it becomes much easier for small impactors to eject the rest of the gas. The researchers calculated that Venus’ atmosphere would only have to start out slightly more massive than Earth’s in order for small impactors to erode the first half of the Earth’s atmosphere, while keeping Venus’ intact. From that point, Schlichting describes the phenomenon as a “runaway process — once you manage to get rid of the first half, the second half is even easier.”

Time zero

During the course of the group’s research, an inevitable question arose: What eventually replaced Earth’s atmosphere? Upon further calculations, Schlichting and her team found the same impactors that ejected gas also may have introduced new gases, or volatiles.

“When an impact happens, it melts the planetesimal, and its volatiles can go into the atmosphere,” Schlichting says. “They not only can deplete, but replenish part of the atmosphere.”

The group calculated the amount of volatiles that may be released by a rock of a given composition and mass, and found that a significant portion of the atmosphere may have been replenished by the impact of tens of thousands of space rocks.

“Our numbers are realistic, given what we know about the volatile content of the different rocks we have,” Schlichting notes.

Going forward, Schlichting hopes to examine more closely the conditions underlying Earth’s early formation, including the interplay between the release of volatiles from small impactors and from Earth’s ancient magma ocean.

“We want to connect these geophysical processes to determine what was the most likely composition of the atmosphere at time zero, when the Earth just formed, and hopefully identify conditions for the evolution of life,” Schlichting says.

Source: MIT News Office