OrbitalHub

NASA Goddard dicit:

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

Wikipedia dicit:

Messier 87 (also known as Virgo A or NGC 4486, generally abbreviated to M87) is a supergiant elliptical galaxy in the constellation Virgo. One of the most massive galaxies in the observable universe, it has a large population of globular clusters—about 12,000 compared with the 150–200 orbiting the Milky Way—and a jet of energetic plasma that originates at the core and extends at least 1,500 parsecs (4,900 light-years), traveling at relativistic speed. It is one of the brightest radio sources in the sky and a popular target for both amateur and professional astronomers.

The French astronomer Charles Messier discovered M87 in 1781, and cataloged it as a nebula. M87 is about 16.4 million parsecs (53 million light-years) from Earth and is the second-brightest galaxy within the northern Virgo Cluster, having many satellite galaxies. Unlike a disk-shaped spiral galaxy, M87 has no distinctive dust lanes. Instead, it has an almost featureless, ellipsoidal shape typical of most giant elliptical galaxies, diminishing in luminosity with distance from the center. Forming around one-sixth of its mass, M87’s stars have a nearly spherically symmetric distribution. Their population density decreases with increasing distance from the core. It has an active supermassive black hole at its core, which forms the primary component of an active galactic nucleus. The black hole was imaged using data collected in 2017 by the Event Horizon Telescope, with a final, processed image released on 10 April 2019.

The galaxy is a strong source of multiwavelength radiation, particularly radio waves. Its galactic envelope extends to a radius of about 150 kiloparsecs (490,000 light-years), where it is truncated—possibly by an encounter with another galaxy. Its interstellar medium consists of diffuse gas enriched by elements emitted from evolved stars.

Video Credit: NASA

NASA Goddard dicit:

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.

Video Credit: NASA Goddard

NASA dicit:

Since arriving at near-Earth asteroid Bennu in December 2018, NASA’s OSIRIS-REx mission has been studying this small world of boulders, rocks, and loose rubble – and looking for a place to touch down. The goal of OSIRIS-REx is to collect a sample of Bennu in mid-2020, and return it to Earth in late 2023.

Bennu turned out to be rockier than anticipated, but mission planners have now identified four sites on its surface that are smooth enough for OSIRIS-REx to collect a sample. The mission will down-select to the final two sites – a primary and a backup – in December 2019. Like the mythological Bennu bird for which the asteroid is named, all of the candidate sample sites refer to birds that can be found in Egypt.

Video Credit: NASA Goddard

NASA dicit:

Its size and surface gravity are much larger than Earth’s, and its radiation environment may be hostile, but a distant planet called K2-18b has captured the interest of scientists all over the world. For the first time, researchers have detected water vapor signatures in the atmosphere of a planet beyond our solar system that resides in the “habitable zone,” the region around a star in which liquid water could potentially pool on the surface of a rocky planet.

Given the high level of activity of its red dwarf star, K2-18b may be more hostile to life as we know it than Earth, as it is likely to be exposed to more high-energy radiation. The planet, discovered by NASA’s Kepler Space Telescope in 2015, also has a mass eight times greater than Earth’s. That means the surface gravity on this planet would be significantly higher than on our planet.

Video Credit: NASA

NASA dicit:

This Hubble time-lapse movie shows the orbits of some of Saturn’s icy moons as they circle the planet over an 18-hour period. The video is composed of 33 Hubble snapshots of the planet, taken June 19 to 20, 2019, by the Wide Field Camera 3.

Saturn’s signature rings are still as stunning as ever. The image reveals that the ring system is tilted toward Earth, giving viewers a magnificent look at the bright, icy structure. Hubble resolves numerous ringlets and the fainter inner rings.

This image reveals an unprecedented clarity only seen previously in snapshots taken by NASA spacecraft visiting the distant planet. Astronomers will continue their yearly monitoring of the planet to track shifting weather patterns and identify other changes. The second in the yearly series, this image is part of the Outer Planets Atmospheres Legacy (OPAL) project. OPAL is helping scientists understand the atmospheric dynamics and evolution of our solar system’s gas giant planets.

Video Credit: NASA