Note: I seem to be having a spot of trouble with publishing so if there is a missing day you’ll know why. I’ve had a couple of misses after the last software update. I’ll get it sorted. Anyway. . .
Now this is a clock! Only off by a second every ten million years!
NASA: An atomic clock that could pave the way for autonomous deep space travel was successfully activated last week and is ready to begin its year-long tech demo, the mission team confirmed on Friday, Aug. 23, 2019. Launched in June, NASA’s Deep Space Atomic Clock is a critical step toward enabling spacecraft to safely navigate themselves in deep space rather than rely on the time-consuming process of receiving directions from Earth.
Developed at NASA’s Jet Propulsion Laboratory in Pasadena, California, the clock is the first timekeeper stable enough to map a spacecraft’s trajectory in deep space while being small enough to fly onboard the spacecraft. A more stable clock can operate farther from Earth, where it needs to work well for longer periods than satellites closer to home.
Atomic clocks, like those used in GPS satellites, are used to measure the distance between objects by timing how long it takes a signal to travel from Point A to Point B. For space exploration, atomic clocks must be extremely precise: an error of even one second means the difference between landing on a planet like Mars or missing it by hundreds of thousands of miles. Up to 50 times more stable than the atomic clocks on GPS satellites, the mercury-ion Deep Space Atomic Clock loses one second every 10 million years, as proven in controlled tests on Earth. Now it will test that accuracy in space.
Navigators currently use refrigerator-size atomic clocks on Earth to pinpoint a spacecraft’s location. Minutes to hours can go by as a signal is sent from Earth to the spacecraft before being returned to Earth, where it is used to create instructions that are then sent back to the spacecraft. A clock aboard a spacecraft would allow the spacecraft to calculate its own trajectory, instead of waiting for navigators on Earth to send that information. This advancement would free missions to travel farther and, eventually, carry humans safely to other planets.
“The goal of the space experiment is to put the Deep Space Atomic Clock in the context of an operating spacecraft — complete with the things that affect the stability and accuracy of a clock — and see if it performs at the level we think it will: with orders of magnitude more stability than existing space clocks,” said navigator Todd Ely, principal investigator of the project at JPL.
In coming months, the team will measure how well the clock keeps time down to the nanosecond. The results begin the countdown to a day when technology can safely help astronauts navigate themselves to other worlds.
Arianespace has confirmed the loss of fight VV15 and the FalconEye1 satellite.
The loss occurred about 2 minutes into the flight. I think the other feed may still be active, but here is a replay.
The loss was evident in the control room even before the commentary had related any indication of something amiss.
The cause is yet to be determined but there the problems seemed to begin at the time of the time of separation of the first stage. I will of course update with more but not until later in the day as I will not be near a computer.
This just shows us that while these launches seem to be a routine event these days, it is very much not so.
One of the worlds most famous (or infamous) volcanoes, this is the view of the recent eruption of Mt. Etna in Italy.
There is a larger version available from NASA – click here. Don’t worry if you have a slower connection, it’s not huge.
NASA: The most recent eruption of Mt. Etna, Italy, began May 30, 2019. New fissure vents opened on the New Southeast Crater, feeding two lava flows that moved down into the Valle del Bove, accompanied by loud explosions. By June 4, when this nighttime ASTER thermal image was acquired, eruption activity had ended.
With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of about 50 to 300 feet (15 to 90 meters), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on Terra. The instrument was built by Japan’s Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and data products.
The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change. Example applications are monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.
The U.S. science team is located at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. The Terra mission is part of NASA’s Science Mission Directorate, Washington.
More information about ASTER is available at http://asterweb.jpl.nasa.gov/.Image Credit:NASA/METI/AIST/Japan Space Systems, and U.S./Japan ASTER Science Team
Here’s the SEDS page for M-59 check out the picture and see the difference.
Hubble et al. (via ESA): This luminous orb is the galaxy NGC 4621, better known as Messier 59. As this latter moniker indicates, the galaxy was listed in the famous catalogue of deep-sky objects compiled by French comet-hunter Charles Messier in 1779. However, German astronomer Johann Gottfried Koehler is credited with discovering the galaxy just days before Messier added it to his collection.
Modern observations show that Messier 59 is an elliptical galaxy, one of the three main kinds of galaxies along with spirals and irregulars. Ellipticals tend to be the most evolved of the trio, full of old, red stars and exhibiting little or no new star formation. Messier 59, however, bucks this trend somewhat; the galaxy does show signs of star formation, with some newborn stars residing within a disc near the core.
Located in the 2000-strong Virgo Cluster of galaxies within the constellation of Virgo (The Virgin), Messier 59 lies approximately 50 million light-years away from us. This image was taken by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys.
When I first heard about the Martian helicopter I dismissed the idea as folly. How would you even get the thing in the air? Well the Martian atmosphere is very thin, but the gravity on Mars is just over a third of what it is here on Earth (Mars and Earth comparison). Here gravity is 9.81 m/s2 and on Mars it is 3.6 m/s2
So the helicopter is reality and will be launching with NASA’s Mars 2020 rover in July 2020. Can you imagine? Flying a helicopter millions of miles away with a multiple minute time delay to account for the time the control signals get to Mars and back, ranging from 4 to 24 minutes is going to be a big challenge.
NASA: A small asteroid has been caught in the process of spinning so fast it’s throwing off material, according to new data from NASA’s Hubble Space Telescope and other observatories.
Images from Hubble show two narrow, comet-like tails of dusty debris streaming from the asteroid (6478) Gault. Each tail represents an episode in which the asteroid gently shed its material — key evidence that Gault is beginning to come apart.
Discovered in 1988, the 2.5-mile-wide (4-kilometer-wide) asteroid has been observed repeatedly, but the debris tails are the first evidence of disintegration. Gault is located 214 million miles (344 million kilometers) from the Sun. Of the roughly 800,000 known asteroids between Mars and Jupiter, astronomers estimate that this type of event in the asteroid belt is rare, occurring roughly once a year.
Watching an asteroid become unglued gives astronomers the opportunity to study the makeup of these space rocks without sending a spacecraft to sample them.
“We didn’t have to go to Gault,” explained Olivier Hainaut of the European Southern Observatory in Germany, a member of the Gault observing team. “We just had to look at the image of the streamers, and we can see all of the dust grains well-sorted by size. All the large grains (about the size of sand particles) are close to the object and the smallest grains (about the size of flour grains) are the farthest away because they are being pushed fastest by pressure from sunlight.”
Gault is only the second asteroid whose disintegration has been strongly linked to a process known as a YORP effect. (YORP stands for “Yarkovsky–O’Keefe–Radzievskii–Paddack,” the names of four scientists who contributed to the concept.) When sunlight heats an asteroid, infrared radiation escaping from its warmed surface carries off angular momentum as well as heat. This process creates a tiny torque that can cause the asteroid to continually spin faster. When the resulting centrifugal force starts to overcome gravity, the asteroid’s surface becomes unstable, and landslides may send dust and rubble drifting into space at a couple miles per hour, or the speed of a strolling human. The researchers estimate that Gault could have been slowly spinning up for more than 100 million years.
Piecing together Gault’s recent activity is an astronomical forensics investigation involving telescopes and astronomers around the world. All-sky surveys, ground-based telescopes, and space-based facilities like the Hubble Space Telescope pooled their efforts to make this discovery possible.
The initial clue was the fortuitous detection of the first debris tail, observed on Jan. 5, 2019, by the NASA-funded Asteroid Terrestrial-Impact Last Alert System (ATLAS) telescope in Hawaii. The tail also turned up in archival data from December 2018 from ATLAS and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) telescopes in Hawaii. In mid-January, a second shorter tail was spied by the Canada–France–Hawaii Telescope in Hawaii and the Isaac Newton Telescope in Spain, as well as by other observers. An analysis of both tails suggests the two dust events occurred around Oct. 28 and Dec. 30, 2018.
Follow-up observations with the William Herschel Telescope and ESA’s (European Space Agency) Optical Ground Station in La Palma and Tenerife, Spain, and the Himalayan Chandra Telescope in India measured a two-hour rotation period for the object, close to the critical speed at which a loose “rubble-pile” asteroid begins to break up.
“Gault is the best ‘smoking gun’ example of a fast rotator right at the two-hour limit,” said team member Jan Kleyna of the University of Hawaii in Honolulu.
An analysis of the asteroid’s surrounding environment by Hubble revealed no signs of more widely distributed debris, which rules out the possibility of a collision with another asteroid causing the outbursts.
The asteroid’s narrow streamers suggest that the dust was released in short bursts, lasting anywhere from a few hours to a few days. These sudden events puffed away enough debris to make a “dirt ball” approximately 500 feet (150 meters) across if compacted together. The tails will begin fading away in a few months as the dust disperses into interplanetary space.
Based on observations by the Canada–France–Hawaii Telescope, the astronomers estimate that the longer tail stretches over half a million miles (800,000 kilometers) and is roughly 3,000 miles (4,800 kilometers) wide. The shorter tail is about a quarter as long.
Only a couple of dozen active asteroids have been found so far. Astronomers may now have the capability to detect many more of them because of the enhanced survey capabilities of observatories such as Pan-STARRS and ATLAS, which scan the entire sky. “Asteroids such as Gault cannot escape detection anymore,” Hainaut said. “That means that all these asteroids that start misbehaving get caught.”
The researchers hope to monitor Gault for more dust events.
The team’s results have been accepted for publication by The Astrophysical Journal Letters.
The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.
Credits: NASA, ESA, K. Meech and J. Kleyna (University of Hawaii), and O. Hainaut (European Southern Observatory)