If that title seems like an obvious statement to you, it’s ok… it seems pretty obvious to me too. But there are those who have been suggesting — for quite some time, actually — that earthquakes can be triggered or strengthened by solar activity; that, in fact, exceptionally powerful solar flares, coronal mass ejections, and other outpourings from our home star can cause the planet’s crust to shift, shake, and shudder.
Except that that’s simply not true — at least, not according to a recent study by researchers from the USGS.
“Recently there’s been a lot of interest in this subject from the popular press, probably because of a couple of larger and very devastating earthquakes. This motivated us to investigate for ourselves whether or not it was true.”
– Jeffrey Love, USGS Research Geophysicist
Even when an earthquake may have been found to occur on the same day as increased solar activity, at other times during even stronger quakes the Sun may have been relatively quiet, and vice versa.
Damage in Anchorage from an earthquake on March 27, 1964. Solar activity at the time was unexceptional. (U.S. Army photo)
“There have been some earthquakes like the 9.5 magnitude Chile quake in 1960 where, sure enough, there were more sunspots and more geomagnetic activity than on average,” said Dr. Love. “But then for the Alaska earthquake in 1964 everything was lower than normal. There’s no obvious pattern between solar activity and seismicity, so our results were inconclusive.”
Basically, even though our planet orbits within the Sun’s outer atmosphere and we are subject to the space weather it creates — and there’s still a lot to be learned about that — observations do not indicate any connection between sunspots, flares, and CMEs and the shifting of our planet’s crust (regardless of what some may like to suggest.)
“It’s natural for scientists to want to see relationships between things,” said Love. “Of course, that doesn’t mean that a relationship actually exists!”
The team’s findings were published in the March 16, 2013 online edition of Geophysical Research Letters.
The bright spot in the center of this HiRISE image may be the 11-meter-wide parachute from Mars 3's descent stage (NASA/JPL-Caltech/Univ. of Arizona)
On May 28, 1971, the Soviet Union launched the Mars 3 mission which, like its previously-launched and ill-fated sibling Mars 2, consisted of an orbiter and lander destined for the Red Planet. Just over six months later on December 2, 1971, Mars 3 arrived at Mars — five days after Mars 2 crashed. The Mars 3 descent module separated from the orbiter and several hours later entered the Martian atmosphere, descending to the surface via a series of parachutes and retrorockets. (Sound familiar?) Once safely on the surface, the Mars 3 lander opened its four petal-shaped covers to release the 4.5-kg PROP-M rover contained inside… and after 20 seconds of transmission, fell silent. Due to unknown causes, the Mars 3 lander was never heard from or seen again.
Until now.
These images show what might be hardware from the Soviet Union’s 1971 Mars 3 lander (NASA/JPL-Caltech/Univ. of Arizona)
The set of images above shows what might be hardware from the 1971 Soviet Mars 3 lander, seen in a pair of images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter.
While following news about Mars and NASA’s Curiosity rover, Russian citizen enthusiasts found four features in a five-year-old image from Mars Reconnaissance Orbiter that resemble four pieces of hardware from the Mars 3 mission: the parachute, heat shield, terminal retrorocket and lander. A follow-up image by the orbiter from last month shows the same features.
“Together, this set of features and their layout on the ground provide a remarkable match to what is expected from the Mars 3 landing, but alternative explanations for the features cannot be ruled out.”
– Alfred McEwen, HiRISE Principal Investigator
The Mars 3 lander (NSSDC)
Vitali Egorov from St. Petersburg, Russia, heads the largest Russian Internet community about Curiosity. His subscribers did the preliminary search for Mars 3 via crowdsourcing. Egorov modeled what Mars 3 hardware pieces should look like in a HiRISE image, and the group carefully searched the many small features in this large image, finding what appear to be viable candidates in the southern part of the scene. Each candidate has a size and shape consistent with the expected hardware, and they are arranged on the surface as expected from the entry, descent and landing sequence.
“I wanted to attract people’s attention to the fact that Mars exploration today is available to practically anyone,” Egorov said. “At the same time we were able to connect with the history of our country, which we were reminded of after many years through the images from the Mars Reconnaissance Orbiter.”
The predicted Mars 3 landing site was at latitude 45 degrees south, longitude 202 degrees east, in Ptolemaeus Crater. HiRISE acquired a large image at this location in November 2007, and promising candidates for the hardware from Mars 3 were found on Dec. 31, 2012.
Candidate features of the Mars 3 retrorockets (top) and lander (bottom)
The candidate parachute is the most distinctive feature in the images (seen above at top.) It is an especially bright spot for this region, about 8.2 yards (7.5 meters) in diameter.
The parachute would have a diameter of 12 yards (11 meters) if fully spread out over the surface, so this is consistent.
“Together, this set of features and their layout on the ground provide a remarkable match to what is expected from the Mars 3 landing, but alternative explanations for the features cannot be ruled out,” said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, Tucson. “Further analysis of the data and future images to better understand the three-dimensional shapes may help to confirm this interpretation.”
The ancient city of Teotihuacan, located about 48 kilometers (30 miles) from Mexico City, is the site of several pyramids built in the period 100 BC to 250 AD. The name means “the place where men become gods.” Astrophotographer César Cantú captured this beautiful view of the stars over the pyramids. Enjoy the ancient landscape and even older starlight!
NASA's Solar Dynamics Observatory captured this image of an M6.5 class flare at 3:16 EDT on April 11, 2013. This image shows a combination of light in wavelengths of 131 and 171 Angstroms. Credit: NASA/SDO.
The Solar Dynamics Observatory captured this view as the Sun let loose with its biggest solar flare of the year so far. It’s not a real big one — a mid-level flare classified as an M6.5 – but an associated coronal mass ejection is heading towards Earth and could spur some nice auroae by this weekend. Spaceweather.com predicts the expanding cloud (see animation below) will probably deliver a glancing blow to Earth’s magnetic field late on April 12th or more likely April 13th. The NOAA Space Prediction Center forecasts this event to cause moderate (G2) Geomagnetic Storm activity, and predicts geomagnetic activity to start in the mid to latter part (UTC) of April 13. They add that the source region is still potent and well-positioned for more geoeffective activity in the next few days.
The magnetic field of sunspot AR1719 erupted on April 11th at 0716 UT, producing an M6-class solar flare. Coronagraph images from the Solar and Heliospheric Observatory show a CME emerging from the blast site of the M6.5 solar flare. Credit: NASA
NASA’s Solar Dynamics Observatory captured this image of an M6.5 class flare at 3:16 am EDT on April 11, 2013. This image shows a combination of light in wavelengths of 131 and 171 Angstroms. Credit: NASA/SDO.
A closeup of an impact crater shows distinctive bright lines and spots on the steep slope, indicating bouncing boulders have fallen down the incline. Credit: NASA/JPL/University of Arizona.
What are the types of things that happen on Mars when we’re not looking? Some things we’ll never know, but scientists with the HiRISE camera on the Mars Reconnaissance Orbiter have seen evidence of bouncing boulders. They haven’t actually captured boulders in the act of rolling and bouncing down the steep slope of an impact crater (but they have captured avalanches while they were happening!)
Instead, they see distinctive bright lines and spots on the side of a crater, and these patterns weren’t there the last time HiRISE imaged this crater 5 years ago (2.6 Mars years ago), in March 2008.
“The discontinuous bright spots indicate bouncing, so we interpret these features as due to boulders bouncing and rolling down the slope,” said HiRISE principal investigator Alfred McEwen, writing on the HiRISE website.
Where did the boulders come from?
“Maybe they fell off of the steep upper cliffs of the crater, although we don’t see any new bright features there that point to the source,” McEwen said. “Maybe the rocks were ejecta from a new impact event somewhere nearby.”
The trails are quite bright, and McEwen said that perhaps the shallow subsurface soil here is generally brighter than the surface soil, just like part of Gusev Crater, as the Spirit rover found. McEwen added that the brightness can’t be from ice because this is a warm equator-facing slope seen in the summer.
Concept of asteroid capture in progress. Credit: NASA.
NASA’s FY2014 budget proposal includes a plan to robotically capture a small near-Earth asteroid and redirect it safely to a stable orbit in the Earth-moon system where astronauts can visit and explore it. A spacecraft would capture an asteroid — which hasn’t been chosen yet, but would be about 7 meters (25 feet) wide — in 2019. Then using an Orion space capsule, a crew of about four astronauts would station-keep with the space rock in 2021 to allow for EVAs for exploration.
NASA has released new images, a video and more information about the mission.
They say that performing all the elements for the proposed asteroid initiative “integrates the best of NASA’s science, technology and human exploration capabilities and draws on the innovation of America’s brightest scientists and engineers.” The mission will combine existing technology along with capabilities being developed to find both large asteroids that pose a hazard to Earth and small asteroids that could be candidates for the proposed mission. NASA says this initiative will help accelerate technology development activities in high-powered solar electric propulsion and take advantage the Space Launch System rocket and Orion spacecraft currently being built, “helping to keep NASA on target to reach the President’s goal of sending humans to Mars in the 2030s.”
Here’s more of NASA’s info:
When astronauts don their spacesuits and venture out for a spacewalk on the surface of an asteroid, how they move and take samples of it will be based on years of knowledge built by NASA scientists and engineers who have assembled and operated the International Space Station, evaluated exploration mission concepts, sent scientific spacecraft to characterize near-Earth objects and performed ground-based analog missions.
As early as the 1970s, NASA examined potential ways to use existing hardware to visit an asteroid to understand better its characteristics. On the International Space Station, scientific investigations and technology demonstrations are improving knowledge of how humans can live and work in space. The agency also has examined many possible mission concepts to help define what capabilities are needed to push the boundaries of space exploration.
During the early space shuttle flights and through assembly of the space station, NASA has relied on testing both in space and on Earth to try out ideas through a host of analog missions, or field tests, that simulate the complexity of endeavors in space.
Concept of Spacecraft with Asteroid Capture Mechanism Deployed. Credit: NASA.
Through 16 missions in the National Oceanic and Atmospheric Administration’s underwater Aquarius Reef Base off the coast of Key Largo, Fla., aquanauts have tested techniques for human space exploration. These underwater tests have been built upon the experience gained by training astronauts in the Neutral Buoyancy Laboratory at NASA’s Johnson Space Center in Houston to assemble and maintain the space station. The NASA Extreme Environment Mission Operations (NEEMO) 15 and 16 missions in 2011 and 2012, respectively, simulated several challenges explorers will face when visiting an asteroid, including how to anchor to and move around the surface of a near-Earth object and how to collect samples of it.
NASA also has simulated an asteroid mission as part of its 2012 Research and Technology Studies ground test at Johnson. During the simulation, a team evaluated how astronauts might do a spacewalk on an asteroid and accomplish other goals. While performing a spacewalk on a captured asteroid will involve different techniques than the activities performed during recent analog exercises, decisions made about ways to best sample an asteroid will be informed by the agency’s on-going concept development and past work.
Artist’s Concept of a Solar Electric Propulsion System. Credit: NASA.
Scientific missions also have investigated the nature of asteroids to provide a glimpse of the origins of the solar system. From the Pioneer 10 spacecraft, which in 1972 was the first to venture into the Main Asteroid Belt, to the Dawn mission, which recently concluded its investigations of asteroid Vesta and is on its way to the dwarf planet Ceres, NASA’s forays help us understand the origins of the solar system and inform decisions about how to conduct missions to distant planetary bodies. Scientists both at NASA and across the world also continue to study asteroids to shed light on their unique characteristics.
As NASA ventures farther into the solar system, the agency continues to simulate and evaluate operations and technical concepts for visiting an asteroid.
NASA has released their budget proposal for 2014 and, as rumored, it includes funding for the preliminary work to begin a mission to capture an asteroid and bring it to lunar orbit. This is part of President Obama’s $3.77 trillion spending plan for the US budget, and the Fiscal Year 2014 request for NASA totals $17.7 billion. This is $50 million less than the request for 2013, and NASA said they had to make some “tough choices” in putting the proposal together. The new proposal appears to hit the Planetary Science program especially hard (no new missions to the outer planets or moons, it appears), but does include money for Plutonium-238 production and additional funding for asteroid detection. But both those enterprises now rest solely with the Planetary Science budget.
“This budget focuses on an ambitious new mission to expand America’s capabilities in space, steady progress on new space and aeronautic technologies, continued success with commercial space partnerships, and far-reaching science programs to help us understand Earth and the universe in which we live,” said NASA administrator Charlie Bolden in a statement. “It keeps us competitive, opens the door to new destinations and vastly increases our knowledge. Our drive to make new discoveries and dare new frontiers continues to improve life for people everywhere and raise the bar of human achievement.”
This certainly is not the final numbers of what NASA could receive. For example, for the FY 2013 budget request, NASA asked for $17.711 billion, but with cuts and sequestration, the final number about $16.6 billion.
The proposed budget for 2014 includes funding for NASA’s ongoing human spaceflight program at the ISS as well as the continuation of building the Space Launch System rocket and Orion deep-space capsule. NASA expected un-crewed test flight planned for as early as 2017 and a crewed flight as early as 2021.
It also continues funding for the James Webb Space Telescope (expected to launch in 2018), but cuts the funding for planetary science – one of NASA’s most successful areas – by $272 million. However, it does include $100 million earmarked for the asteroid detection program, which was added to the Planetary Science budget. It also includes funding for another Mars rover very similar to Curiosity, expected to be launched in 2020.
In an interesting move, the budget proposes consolidating the NASA education and outreach programs with the National Science Foundation, the Department of Education, and the Smithsonian Institution. STEM outreach is another of NASA’s success stories, but it appears some of NASA’s education budget is going to other agencies as part of government-wide STEM restructuring.
Graph from NASA’s 2014 Budget Request.
This video provides some of the highlights, but below is more information:
Here are the highlights of the 2014 budget proposal for NASA:
While making tough choices, NASA says this budget reinforces the agency’s current balanced portfolio of aeronautics and space technology development, Earth and space science, the development of rockets and capsules to carry explorers deeper into space, and the use of innovative commercial partnerships for crew and cargo transport to the International Space Station.
Includes funding needed to develop a Commercial Crew capability, with the intent of supporting a new industry that regains the capability to send American astronauts into space from U.S. soil and ends the need to pay foreign providers to transport American astronauts to the International Space Station.
Increases investment in space technologies, such as advanced in-space propulsion and space propellant storage, which are necessary to increase America’s capabilities in space, bring the cost of space exploration down, and pave the way for other Federal Government and commercial space activities.
Fully funds the Space Launch System heavy-lift rocket and Orion Multi-Purpose Crew Vehicle, two key elements for pushing the boundaries of human space exploration. This funding level will enable a flight test of Orion in 2014 and the Space Launch System in 2017.
Keeps development of the James Webb SpaceTelescope, the more powerful successor to the Hubble SpaceTelescope, on track for a 2018 launch.
Provides over $1.8 billion for Earth Science to revamp the Landsat program, develop climate sensors for the Joint Polar Satellite System, and conduct numerous other satellite and research efforts.
Begins work on a mission to rendezvous with—and then move—a small asteroid. Astronauts would later visit the asteroid and return samples to Earth, achieving one of the agency’s major goals in a more cost-effective manner.
Of the asteroid mission Bolden said, “This mission represents an unprecedented technological feat that will lead to new scientific discoveries and technological capabilities and help protect our home planet. This asteroid initiative brings together the best of NASA’s science, technology and human exploration efforts to achieve the president’s goal of sending humans to an asteroid by 2025. We will use existing capabilities such as the Orion crew capsule and Space Launch System (SLS) rocket, and develop new technologies like solar electric propulsion and laser communications — all critical components of deep space exploration.”
Continues the agency’s important role in the Nation’s aeronautics research and development portfolio, including a new initiative to make lighter composite materials more easily useable in aviation.
Funds research on the International Space Station, while identifying efficiencies in operations and space flight support.
Consolidates $47.5 million of small science, technology, engineering, and mathematics (STEM) education programs from across NASA into larger programs at other agencies to achieve the best return on investment, while attaining tangible Government-wide STEM education goals. The Budget preserves $67.5 million for the Space Grant and Global Learning and Observations to Benefit the Environment programs at NASA, as well as key minority-serving education programs, and refocuses an additional $26.8 million from other NASA education and outreach programs to facilitate the wider application of its best education assets in close coordination with the National Science Foundation, the Department of Education, and the Smithsonian Institution.
This artist's concept illustrates how charged water particles flow into the Saturnian atmosphere from the planet's rings, causing a reduction in atmospheric brightness. Credit: NASA/JPL-Caltech/Space Science Institute/University of Leicester
Astronomers have known for years there was water in Saturn’s upper atmosphere, but they weren’t sure exactly where it was coming from. New observations have found water is raining down on Saturn, and it is coming from the planet’s rings.
“Saturn is the first planet to show significant interaction between its atmosphere and ring system,” said James O’Donoghue, a postgraduate researcher at the University of Leicester and author of a new paper published in the journal Nature. “The main effect of ring rain is that it acts to ‘quench’ the ionosphere of Saturn, severely reducing the electron densities in regions in which it falls.”
Using the Keck Observatory, O’Donoghue and a team of researchers found charged water particles falling from the planet’s rings into Saturn’s atmosphere. They also found the extent of the ring-rain is far greater, and falls across larger areas of the planet, than previously thought. The work reveals the rain influences the composition and temperature structure of parts of Saturn’s upper atmosphere.
O’Donoghue said the ring’s effect on electron densities is important because it explains why, for many decades, observations have shown electron densities to be unusually low at some latitudes at Saturn.
“It turns out a major driver of Saturn’s ionospheric environment and climate across vast reaches of the planet are ring particles located 120,000 miles [200,000 kilometers] overhead,” said Kevin Baines, a co-author on the paper, from the Jet Propulsion Laboratory. “The ring particles affect which species of particles are in this part of the atmospheric temperature.”
In the early 1980s, images from NASA’s Voyager spacecraft showed two to three dark bands on Saturn and scientists theorized that water could have been showering down into those bands from the rings. Then astronomers using ESA’s Infrared Observatory discovered the presence of trace amounts of water in Saturn’s atmosphere back in 1997, but couldn’t really find an explanation for why it was there and how it got there.
But the bands seen by Voyager were not seen again until 2011 as well, when the team observed the planet with Keck Observatory’s NIRSPEC, a near-infrared spectrograph that combines broad wavelength coverage with high spectral resolution, allowing the observers to clearly see subtle emissions from the bright parts of Saturn.
The ring rain’s effect occurs in Saturn’s ionosphere (Earth has a similar ionosphere), where charged particles are produced when the otherwise neutral atmosphere is exposed to a flow of energetic particles or solar radiation. When the scientists tracked the pattern of emissions of a particular hydrogen molecule consisting of three hydrogen atoms (rather than the usual two), they expected to see a uniform planet-wide infrared glow.
What they observed instead was a series of light and dark bands with a pattern mimicking the planet’s rings. Saturn’s magnetic field “maps” the water-rich rings and the water-free gaps between rings onto the planet’s atmosphere.
They surmised that charged water particles from the planet’s rings were being drawn towards the planet by Saturn’s magnetic field and neutralizing the glowing triatomic hydrogen ions. This leaves large “shadows” in what would otherwise be a planet-wide infrared glow. These shadows cover 30 to 43 percent of the planet’s upper atmosphere surface from around 25 to 55 degrees latitude. This is a significantly larger area than suggested by the Voyager images.
Both Earth and Jupiter have a very uniformly glowing equatorial region. Scientists expected this pattern at Saturn, too, but they instead saw dramatic differences at different latitudes.
“Where Jupiter is glowing evenly across its equatorial regions, Saturn has dark bands where the water is falling in, darkening the ionosphere,” said Tom Stallard, one of the paper’s co-authors at Leicester. “We’re now also trying to investigate these features with an instrument on NASA’s Cassini spacecraft. If we’re successful, Cassini may allow us to view in more detail the way that water is removing ionized particles, such as any changes in the altitude or effects that come with the time of day.”
Comet C/2011 L4 PANSTARRS on the evening of April 9, 2013 from Austria. Dust released when the sun vaporizes the comet's ice is pushed back by the pressure of sunlight to form the tail. Click to enlarge. Credit: Michael Jaeger
It’s falling out of the news but Comet PANSTARRS still lives! You can still see it in a clear sky near you with nothing more than a pair of binoculars. And thanks to guidance from the bright zigzag of Cassiopeia, it’s easier than ever to find. Would that we had had this star group to point up comet-ward in March when PANSTARRS was brightest!
The comet marches along through Cassiopeia the Queen in April. The map shows the evening sky facing northwest about 90 minutes after sunset. Comet positions are shown every 5 nights. Stellarium
Start looking about 75-90 minutes after sunset or the same amount of time before sunrise. Yes, the comet is visible now at both dusk and dawn. Currently it shines at about 4.5-5 magnitude and might still be faintly visible with the naked from a very dark sky location. In 35-50mm binoculars it will look like a faint, fuzzy streak of light with a brighter head. Telescopes still give a wonderful view of the bright nucleus and shapely tail.
While the northern U.S., Canada and Europe have good views of PANSTARRS at both dusk and dawn, sky watchers in the southern U.S. have their best views at dawn. This map shows the sky at the start of dawn facing northeast about 90 minutes before sunrise. Stellarium
The other night a student who helps run our local planetarium described it as looking like a “real comet” through the telescope, the way textbook and online photos had led him to anticipate. Binoculars or telescope will show a misty, plume-like tail, but wide-field, time-exposure photography reveals the comet’s unbelievably broad fan of dust.
Comet PANSTARRS moves along a steeply tilted orbit that takes it far above and below the plane of the planets. Right now it’s high above Earth’s north pole and we see its tail broadside. The comet takes about 106,000 years to complete an orbit around the sun. Credit: NASA/JPL/Bob King
The reason for this unusual appearance has much to do with perspective. PANSTARRS is sailing back into deep space directly above the plane of the planets. With the tail blown back by the pressure of sunlight, we look up and across a distance of more than 125 million miles (201 million km) to see it spread like a deck of cards across the constellation Cassiopeia.
Comet PANSTARRS a week ago when it passed near the Andromeda Galaxy (at left). Details: 300mm f/2.8, ISO 800 and 90-second exposure. Credit: Bob King
In the northern U.S., Cassiopeia is higher up in both morning and evening skies and easy to spot. Once you’ve found its familiar shape, focus your binoculars on the brightest star nearest the comet, and slowly work your way in its direction. Skywatchers in the northern U.S., Canada and Europe are favored because Cassiopeia is a northern constellation and higher up in the sky at both dusk and dawn. Observers in the southern U.S. will get their best views around the start of dawn.
Artist's rendition of TESS in space. (Credit: MIT Kavli Institute for Astrophysics Research).
Move over Kepler. NASA has recently green-lighted two new missions as part of its Astrophysics Explorer Program.
These come as the result of four proposals submitted in 2012. The most anticipated and high profile mission is TESS, the Transiting Exoplanet Survey Satellite.
Slated for launch in 2017, TESS will search for exoplanets via the transit method, looking for faint tell-tale dips in brightness as the unseen planet passes in front of its host star. This is the same method currently employed by Kepler, launched in 2009. Unlike Kepler, which stares continuously at a single segment of the sky along the galactic plane in the direction of the constellations Cygnus, Hercules, and Lyra, TESS will be the first dedicated all-sky exoplanet hunting satellite.
The mission will be a partnership of the Space Telescope Science Institute, the MIT Lincoln Laboratory, the NASA Goddard Spaceflight Center, Orbital Sciences Corporation, the Harvard-Smithsonian Center for Astrophysics and the MIT Kavli Institute for Astrophysics and Space Research (MKI).
TESS will launch onboard an Orbital Sciences Pegasus XL rocket released from the fuselage of a Lockheed L-1011 aircraft, the same system that deployed IBEX in 2008 & NuSTAR in 2012. NASA’s Interface Region Imaging Spectrograph (IRIS) will also launch using a Pegasus XL rocket this summer in June.
An Orbital Sciences Pegasus XL rocket attached to the fuselage of an L1011 for the launch of IBEX. (Credit: NASA).
“TESS will carry out the first space-borne all-sky transit survey, covering 400 times as much sky as any previous mission. It will identify thousands of new planets in the solar neighborhood, with a special focus on planets comparable in size to the Earth,” said George Riker, a senior researcher from MKI.
TESS will utilize four wide angle telescopes to get the job done. The effective size of the detectors onboard is 192 megapixels. TESS is slated for a two year mission. Unlike Kepler, which sits in an Earth-trailing heliocentric orbit, TESS will be in an elliptical path in Low Earth Orbit (LEO).
TESS will examine approximately 2 million stars brighter than 12th magnitude including 1,000 of the nearest red dwarfs. Not only will TESS expand the growing catalog of exoplanets, but it is also expected to find planets with longer orbital periods.
One dilemma with the transit method is that it favors the discovery of planets with short orbital periods, which are much more likely to be seen transiting their host star from a given vantage point in space.
TESS will also serve as a logical progression from Kepler to later proposed exoplanet search platforms. TESS will also discover candidates for further scrutiny by as the James Webb Space Telescope to be launched in 2018 and the High Accuracy Radial Velocity Planet Searcher (HARPS) spectrometer based at La Silla Observatory in Chile.
Artist’s conception of NICER on the exterior of the International Space Station. (Credit: NASA).
Also on the board for launch in 2017 is NICER, the Neutron Star Interior Composition Explorer to be placed on the exterior of the International Space Station. NICER will employ an array 56 telescopes which will collect and study X-rays from neutron stars. NICER will specialize in the study of a particular sub-class of neutron star known as millisecond pulsars. The X-ray telescopes are in a configuration utilizing a set of nested glass shells looking like the layers of an onion.
Observing pulsars in the X-ray range of the spectrum will offer scientists tremendous insight into their inner workings and structure. The International Space Station offers a unique vantage point to do this sort of science. Like the Alpha Magnetic Spectrometer (AMS-02), the power requirements of NICER dictate that it cannot be a free-flying satellite. X-Ray astronomy must also be done above the hindering effects of the Earth’s atmosphere.
NICER will be deployed as an exterior payload aboard an ISS ExPRESS Logistics Carrier. These are unpressurized platforms used for experiments that must be directly exposed to space.
Another fascinating project working in tandem with NICER is SEXTANT, the Station Explorer for X-ray Timing And Navigation Technology. This project seeks to test the precision of millisecond pulsars for interplanetary navigation.
“They (pulsars) are extremely reliable celestial clocks and can provide high-precision timing just like the atomic signals supplied through the 26-satellite military operated Global Positioning System (GPS),” said NASA Goddard scientist Zaven Arzoumanian. The chief difficulty with relying on this system for interplanetary journeys is that the signal gets progressively weaker the farther you travel from the Earth.
“Pulsars, on the other hand, are accessible in virtually every conceivable flight regime, from LEO to interplanetary and deepest space,” said NICER/SEXTANT principle investigator Keith Gendreau.
Both NICER and TESS follow the long legacy of NASA’s Astrophysics Explorer Program, which can be traced all the way back to the launch Explorer 1. This was the very first U.S. satellite launched in 1958. Explorer 1 discovered the Van Allen radiation belts surrounding the Earth.
(From left) William Pickering, James Van Allen, and Wernher von Braun hold aloft a mock up of Explorer 1 shortly after launch. (Credit NASA/JPL-Caltech).
“The Explorer Program has a long and stellar history of deploying truly innovative missions to study some of the most exciting questions in space science,” stated NASA associate administrator for science John Grunsfeld. “With these missions, we will learn about the most extreme states of matter by studying neutron stars and we will identify many nearby star systems with rocky planets in the habitable zones for further study by telescopes such as the James Webb Space Telescope.”
Of course, Grunsfeld is referring to planets orbiting red dwarf stars, which will be targeted by TESS. These are expected have a habitable zone much closer to their primary star than our own Sun. It has even been suggested by MIT scientists that the first exoplanets visited by humans on some far off date might be initially discovered by TESS. The spacecraft may also discover future targets for follow up spectroscopic analysis, the best chance of discovering alien life on an exoplanet in the next 50 years. One can imagine the excitement that a positive detection of a chemical exclusive to life as we know it such as chlorophyll in the spectra of a far of world would generate. More ominously, detection of such synthetic elements as plutonium in the atmosphere of an exoplanet might suggest we found them… but alas, too late.
But on a happier note, it’ll be exciting times for space exploration to see both projects get underway. Perhaps human explorers will indeed one day visit the worlds discovered by TESS… and use navigation techniques pioneered by SEXTANT to do it!
