NASA’s Parker Solar Probe mission has returned unprecedented data from near the Sun, culminating in new discoveries published on December 4, 2019, in the journal Nature. Among the findings are new understandings of how the Sun’s constant outflow of material, the solar wind, behaves. Seen near Earth — where it can interact with our planet’s natural magnetic field and cause space weather effects that interfere with technology — the solar wind appears to be a relatively uniform flow of plasma. But Parker Solar Probe’s observations reveal a complicated, active system not seen from Earth.
The Kepler space telescope is a retired space telescope launched by NASA to discover Earth-size planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched on March 7, 2009, into an Earth-trailing heliocentric orbit. The principal investigator was William J. Borucki. After nine years of operation, the telescope’s reaction control system fuel was depleted, and NASA announced its retirement on October 30, 2018.
Designed to survey a portion of Earth’s region of the Milky Way to discover Earth-size exoplanets in or near habitable zones and estimate how many of the billions of stars in the Milky Way have such planets, Kepler’s sole scientific instrument is a photometer that continually monitored the brightness of approximately 150,000 main sequence stars in a fixed field of view. These data are transmitted to Earth, then analyzed to detect periodic dimming caused by exoplanets that cross in front of their host star. Only planets whose orbits are seen edge-on from Earth can be detected. During its over nine and a half years of service, Kepler observed 530,506 stars and detected 2,662 planets.
LISA Pathfinder, a mission led by ESA (the European Space Agency) that included NASA contributions, successfully demonstrated technologies needed to build a future space-based gravitational wave observatory, a tool for detecting ripples in space-time produced by, among other things, merging black holes. A team of NASA scientists leveraged LISA Pathfinder’s record-setting sensitivity for a different purpose much closer to home — mapping microscopic dust shed by comets and asteroids.
Most of these particles, known as micrometeroids, have masses measured in micrograms, similar to a small grain of sand. But at speeds reaching 40,000 mph (64,000 kph), even micrometeoroids pack a punch.
The NASA team, led by Ira Thorpe at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, detected 54 impacts during the mission, which lasted from 2015 to 2017. Modeling the strikes allowed the researchers to determine what kinds of objects shed the dust. The findings are broadly consistent with existing ideas of what generates micrometeroids found near Earth. The dusty culprits are mostly short-period comets whose orbits are determined by Jupiter. Comets with longer periods, like Halley’s comet, also contributed dust that LISA Pathfinder sensed.
The new measurements could help refine dust models used by researchers in a variety of studies, from understanding the physics of planet formation to estimating impact risks for current and future spacecraft.
Video Credit: NASA’s Goddard Space Flight Center/Scott Wiessinger (USRA): Lead Producer/Francis Reddy (University of Maryland College Park): Lead Science Writer/Tom Bridgman (GST): Lead Visualizer/James Ira Thorpe (NASA/GSFC): Scientist/Walt Feimer (KBRwyle): Animator/Scott Wiessinger (USRA): Narrator
In October 2019, technicians and engineers successfully performed a critical test on NASA’s James Webb Space Telescope by fully deploying and properly tensioning each of its five uniquely sized sunshield layers, putting them into the same positions they will have in space. To observe distant parts of the universe humans have never seen before, the Webb observatory is equipped with an arsenal of revolutionary technologies, making it the most sophisticated and complex space science telescope ever created. Among the most challenging of these technologies is the five-layer sunshield, designed to protect the observatory’s mirrors and scientific instruments from light and heat, primarily from the Sun. Due to the telescope’s size, shape and thermal performance requirements, the sunshield must be both big and complex. As if that’s not challenging enough, it also must be very lightweight, fit inside a standard 5-meter (16-foot) diameter rocket fairing, survive the perils of launch, and accurately deploy into its required shape, with only a single chance to get it right. Following Webb’s successful sunshield test within Northrop Grumman’s Redondo Beach, California facility, team members have begun the long process of perfectly folding the sunshield back into its stowed configuration for flight, which occupies a drastically smaller volume than when it is fully deployed.
Video Credit: Credit: NASA’s Goddard Space Flight Center/Mike McClare/Michael Starobin/Mike Menzel/Sophia Roberts
On schedule to launch in the mid-2020s, NASA’s Wide Field Infrared Survey Telescope (WFIRST) mission will help uncover some of the biggest mysteries in the cosmos. The state-of-the-art telescope on the WFIRST spacecraft will play a significant role in this, providing the largest picture of the universe ever seen with the same depth and precision as the Hubble Space Telescope.
The telescope for WFIRST has successfully passed its preliminary design review, a major milestone for the mission. This means the telescope has met the performance, schedule, and budget requirements to advance to the next stage of development, where the team will finalize its design.
WFIRST is a high-precision survey mission that will advance our understanding of fundamental physics. WFIRST is similar to other space telescopes, like Spitzer and the James Webb Space Telescope, in that it will detect infrared light, which is invisible to human eyes. Earth’s atmosphere absorbs infrared light, which presents challenges for observatories on the ground. WFIRST has the advantage of flying in space, above the atmosphere.
The WFIRST telescope will collect and focus light using a primary mirror that is 2.4 meters in diameter. While it’s the same size as the Hubble Space Telescope’s main mirror, it is only one-fourth the weight, showcasing an impressive improvement in telescope technology.
The mirror gathers light and sends it on to a pair of science instruments. The spacecraft’s giant camera, the Wide Field Instrument (WFI), will enable astronomers to map the presence of mysterious dark matter, which is known only through its gravitational effects on normal matter. The WFI will also help scientists investigate the equally mysterious “dark energy,” which causes the universe’s expansion to accelerate. Whatever its nature, dark energy may hold the key to understanding the fate of the cosmos.
In addition, the WFI will survey our own galaxy to further our understanding of what planets orbit other stars, using the telescope’s ability to sense both smaller planets and more distant planets than any survey before (planets orbiting stars beyond our Sun are called “exoplanets”). This survey will help determine whether our solar system is common, unusual, or nearly unique in the galaxy. The WFI will have the same resolution as Hubble, yet has a field of view that is 100 times greater, combining excellent image quality with the power to conduct large surveys that would take Hubble hundreds of years to complete.
WFIRST’s Coronagraph Instrument (CGI) will directly image exoplanets by blocking out the light of their host stars. To date, astronomers have directly imaged only a small fraction of exoplanets, so WFIRST’s advanced techniques will expand our inventory and enable us to learn more about them. Results from the CGI will provide the first opportunity to observe and characterize exoplanets similar to those in our solar system, located between three and 10 times Earth’s distance from the Sun, or from about midway to Jupiter to about the distance of Saturn in our solar system. Studying the physical properties of exoplanets that are more similar to Earth will take us a step closer to discovering habitable planets.
Video Credit: NASA’s Goddard Space Flight Center/Scott Wiessinger (USRA): Lead Producer/Michael Lentz (USRA): Lead Animator/Claire Andreoli (NASA/GSFC): Lead Public Affairs Officer/Francis Reddy (University of Maryland College Park): Science Writer/Ashley Balzer (GSFC Interns): Writer/Scott Wiessinger (USRA): Narrator/Scott Wiessinger (USRA): Editor
When a new NASA space telescope opens its eyes in the mid 2020s, it will peer at the universe through some of the most sophisticated sunglasses ever designed. This multi-layered technology, the coronagraph instrument, might more rightly be called “starglasses”: a system of masks, prisms, detectors and even self-flexing mirrors built to block out the glare from distant stars — and reveal the planets in orbit around them. Normally, that glare is overwhelming, blotting out any chance of seeing orbiting planets. The star’s photons — particles of light — swamp those from the planet when they hit the telescope.
WFIRST’s coronagraph just completed a major milestone: a preliminary design review by NASA. The instrument has met all design, schedule and budget requirements, and can now proceed to the next phase, b uilding hardware for flight. The WFIRST mission’s coronagraph is meant to demonstrate the power of increasingly advanced technology. As it captures light directly from large, gaseous exoplanets, and from disks of dust and gas surrounding other stars, it will point the way to the future: single pixel “images” of rocky planets the size of Earth. Then the light can be spread into a rainbow spectrum, revealing which gases are present in the planet’s atmosphere — perhaps oxygen, methane, carbon dioxide, and maybe even signs of life.
The two flexible mirrors inside the coronagraph are key components. As light that has traveled tens of light-years from an exoplanet enters the telescope, thousands of actuators move like pistons, changing the shape of the mirrors in real time. The flexing of these “deformable mirrors” compensates for tiny flaws and changes in the telescope’s optics. Changes on the mirrors’ surfaces are so precise they can compensate for errors smalle r than the width of a strand of DNA. These mirrors, in tandem with high-tech “masks,” another major advance, squelch the star’s diffraction as well – the bending of light waves around the edges of light-blocking elements inside the coronagraph.
The result: blinding starlight is sharply dimmed, and faintly glowing, previously hidden planets appear. The star-dimming technology also could bring the clearest-ever images of distant star systems’ formative years — when they are still swaddled in disks of dust and gas as infant planets take shape inside.
The instrument’s deformable mirrors and other advanced technology — known as “active wavefront control” — should mean a leap of 100 to 1,000 times the capability of previous coronagraphs.
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