Tag Archives: space news

Astronomers detect hot gas bubble swirling around the Milky Way’s black hole

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Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have spotted signs of a ‘hot spot’ orbiting Sagittarius A*, the black hole at the centre of our galaxy. The finding helps us better understand the enigmatic and dynamic environment of our supermassive black hole.

“We think we’re looking at a hot bubble of gas zipping around Sagittarius A* on an orbit similar in size to that of the planet Mercury, but making a full loop in just around 70 minutes. This requires a mind blowing velocity of about 30% of the speed of light!” says Maciek Wielgus of the Max Planck Institute for Radio Astronomy in Bonn, Germany, who led the study published today, Sept 22, 2022 in Astronomy & Astrophysics.

The orbit of the hot spot around Sagittarius A*

The observations were made with ALMA in the Chilean Andes — a radio telescope co-owned by the European Southern Observatory (ESO) — during a campaign by the Event Horizon Telescope (EHT) Collaboration to image black holes. In April 2017 the EHT linked together eight existing radio telescopes worldwide, including ALMA, resulting in the recently released first ever image of Sagittarius A.

To calibrate the EHT data, Wielgus and his colleagues, who are members of the EHT Collaboration, used ALMA data recorded simultaneously with the EHT observations of Sagittarius A. To the team’s surprise, there were more clues to the nature of the black hole hidden in the ALMA-only measurements.

By chance, some of the observations were done shortly after a burst or flare of X-ray energy was emitted from the centre of our galaxy, which was spotted by NASA’s Chandra Space Telescope. These kinds of flares, previously observed with X-ray and infrared telescopes, are thought to be associated with so-called ‘hot spots’, hot gas bubbles that orbit very fast and close to the black hole.

The flares were long thought to originate from magnetic interactions in the very hot gas orbiting very close to Sagittarius A*, and the new findings support this idea. “Now we find strong evidence for a magnetic origin of these flares and our observations give us a clue about the geometry of the proces,” says co-author Monika Mościbrodzka from Radboud University.

The observations confirm some of the previous discoveries made by the GRAVITY instrument at ESO’s Very Large Telescope (VLT), which observes in the infrared. The data from GRAVITY and ALMA both suggest the flare originates in a clump of gas swirling around the black hole at about 30% of the speed of light in a clockwise direction in the sky, with the orbit of the hot spot being nearly face-on.

What Has Changed on Jupiter from 2006 to Now? Hubble captures all in detail

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This (above) latest image of Jupiter was captured by Hubble Space Telescope on 25 August 2020, when the planet was 653 million kilometres from Earth, giving clues on updated weather report on the monster planet’s turbulent atmosphere. A remarkable new storm is brewing, and a cousin of the Great Red Spot is changing colour again. The tiny new image is Jupiter’s icy moon Europa.

Hubble’s new snapshot appears at mid-northern latitudes as a bright, white, stretched-out storm moving at 560 kilometres per hour. This single plume erupted on 18 August 2020 and another has since appeared.

Unlike other common storms in this region, this particular disturbance appears to have more structure behind it than observed in the past storms. Trailing behind the plume are small, counterclockwise dark clumps also not seen in the past, which could mean the beginning of a longer-lasting northern hemisphere spot, perhaps to rival the legendary Great Red Spot that dominates the southern hemisphere.

Great Red Spot

Hubble shows that the Great Red Spot, rolling counterclockwise in the planet’s southern hemisphere, is ploughing into the clouds ahead of it, forming a cascade of white and beige ribbons, while its current exceptionally rich red colour, with its core and outermost band, is appearing deeper red.

Researchers say the Great Red Spot now measures about 15 800 kilometres across, big enough to swallow the Earth. The super-storm is still shrinking, as noted in telescopic observations dating back to 1930, but its rate of shrinkage appears to have slowed though the reason for its dwindling size remains a  mystery.

The NASA/ESA Hubble Space Telescope is giving astronomers their most detailed view yet of a second red spot emerging on Jupiter. For the first time in history, astronomers have witnessed the birth of a new red spot on the giant planet, which is located half a billion miles away (about 800 thousand kilometres). The storm is roughly one-half the diameter of its bigger and legendary cousin, the Great Red Spot. Researchers suggest that the new spot may be related to a possible major climate change in Jupiter’s atmosphere.
Credit: NASA, ESA, A. Simon-Miller (NASA/GSFC), and I. de Pater (University of California Berkeley)

Researchers are noticing that another feature has changed: the Oval BA, nicknamed by astronomers as Red Spot Jr., which appears just below the Great Red Spot in this image. For the past few years, Red Spot Jr. has been fading in colour to its original shade of white after appearing red in 2006. However, now the core of this storm appears to be darkening to a reddish hue. This could hint that Red Spot Jr. is on its way to reverting to a colour more similar to that of its cousin.

Hubble’s image shows that Jupiter is clearing out its higher-altitude white clouds, especially along the planet’s equator, which is enveloped in an orangish hydrocarbon smog.

Jupiter’s icy moon Europa is visible to the left of the gas giant. Europa is already thought to harbour a liquid ocean beneath its icy crust, making this moon one of the main targets in the search for habitable worlds beyond Earth.

Water vapour

In 2013 it was announced that the Hubble Space Telescope discovered water vapour erupting from the frigid surface of Europa, in one or more localised plumes near its south pole. ESA’s JUpiter ICy moons Explorer, a mission planned for launch in 2022, aims to explore both Jupiter and three of its largest moons: Ganymede, Callisto, and Europa.

Hubble also captured a new multiwavelength observation in ultraviolet/visible/near-infrared light of Jupiter on 25 August 2020, which is giving researchers an entirely new view of the giant planet. Hubble’s near infrared imaging, combined with ultraviolet views, provides a unique panchromatic look that offers insights into the altitude and distribution of the planet’s haze and particles. This complements Hubble’s visible-light picture that shows the ever-changing cloud patterns.

WATCH LIVE TODAY: Starlink Mission all set to take off today

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US private space agency SpaceX is targeting Friday, August 7 at 1:12 a.m. EDT, 5:12 UTC, for launch of its tenth Starlink mission which will include 57 Starlink satellites and 2 satellites from BlackSky, a Spaceflight customer.

The standard vehicle Falcon 9 will lift off from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida. In case you miss the event, a backup opportunity is available on Saturday, August 8 at 12:50 a.m. EDT, 4:50 UTC.

You can watch the launch webcast here, starting about 15 minutes before liftoff.

Sequential Deployment

Falcon 9’s first stage previously supported Crew Dragon’s first demonstration mission to the International Space Station, launch of the RADARSAT Constellation Mission, and the fourth and seventh Starlink missions. Following stage separation, SpaceX will land Falcon 9’s first stage on the “Of Course I Still Love You” droneship, which will be stationed in the Atlantic Ocean.

The BlackSky Global spacecraft will deploy sequentially beginning 1 hour and 1 minute after liftoff, and the Starlink satellites will deploy approximately 1 hour and 33 minutes after liftoff. Starlink satellites will be deployed in a circular orbit, as was done on the first through fourth Starlink missions.

Weather Forecast

The weather forecast is favorable for SpaceX’s Friday early hours launch from Kennedy Space Center, the Space Force said Wednesday. “The primary weather concern for launch day will be mid- and upper-level clouds streaming across the region from the south along with cumulus clouds over the nearshore waters,” 45th Weather Squadron forecasters said on Wednesday.

The 10th Starlink launch has been delayed nearly 10 times due to technical hurdles so far and several attempts in June and July were rolled back for additional hardware work. Today’s launch will be the booster’s fifth flight.

All Starlink satellites  on this flight are equipped with a deployable visor to block sunlight from hitting the brightest spots of the spacecraft – a measure SpaceX has taken as part of their work with leading astronomical groups to mitigate satellite reflectivity.

Wind blows, ground moves on Mars, says study after INSIGHT lander findings

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A new study by researchers at Kyushu University’s International Institute for Carbon-Neutral Energy Research, Fukuoka in  Japan after comparing findings of Mars Insight lander after comparing with our own planet Earth, found Mars might seem like a “dead” planet, but even there, the wind blows and the ground moves.

Similar to earthquakes, the ambient seismic noise rippling mainly due to ocean activity to peek underground at the structure of the Earth’s interior. Can we do the same on Mars without ocean? The Japanese researchers’ study, published in Geophysical Research Letters, is based on data collected by NASA’s InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) Martian lander, which landed on Mars on November 26, 2018.

This is ambient noise on the Mars CREDIT: Takeshi Tsuji, I2CNER, Kyushu University

 

 

The InSight lander placed a seismometer on the surface of Mars and its readings collected between February and June 2019 revealed the existence of several hundred marsquakes, most of them much weaker than the quakes typically felt on Earth, although some reached a maximum magnitude of 4.

The data from these “microtremors” helped to determine the directions of propagation and directional intensity. Study co-author Tatsunori Ikeda said, “Our polarization analysis revealed that seismic waves of different frequencies and types showed different patterns of variation over the course of the Martian day. The temporal variations in low-frequency P-waves were related to distant changes in wind and solar irradiation, and the low-frequency Rayleigh waves were related to the wind direction in the region near the lander.”

This artist’s concept depicts NASA’s InSight lander after it has deployed its instruments on the Martian surface (NASA)

Higher-frequency ambient noises were, of course, made by vibration of the lander itself and hence, these microtremors of different types and frequencies likely have different sources, and some are probably influenced by geological structures, noted the scientists.

Mars Interior

These differences between the dominant sources of Martian microtremors may help in efforts to identify geological structures in Mars’s interior, as we inferred the lithological boundary beneath the seismometer from high frequency ambient noise.

A single seismometer is not yet enough to reconstruct images of the planet’s interior as usually done on Earth from data networks of multiple seismometers. But this analysis of the InSight lander’s seismic data is a key step toward achieving that goal on Mars, said scientists of the study.

The study’s senior author Takeshi Tsuji said:”These results demonstrate the feasibility of ambient noise methods on Mars. Future seismic network projects will enable us to model and monitor the planet’s interior geological structure, and may even contribute to resource exploration on Mars, such as for buried ice.”

Sunday May 6: Solar Storm to cause Mobile, TV, Tech Blackout on Earth?

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US space agency NASA has informed that a solar storm brewing on Sun is flaring up splitting huge sun storms which may reach earth on Sunday, May 6. It said a coronal hole or sun spot has opened up releasing huge swarm of cosmic rays which may take 8 minutes to reach earth.

The space weather watching unit of National Oceanic and Atmospheric Administration (NOAA) said the solar tsunami can create an aurora or polar lights when it hits earth. Astronomers have estimated that three such solar storms are likely to reach earth on May 6, to be precise, the Indian Ocean and India is very much within the target area.

The storm classified as G-1 or ‘minor’ is the biggest since 2004 and it could trigger sparks and melt soil on Moon, while its impact on Earth is still not comprehended by astronomers but similar storms had apparently given birth to origin of life on earth.

A section of scientists warned that the solar storms on Sunday could be severe enough to disrupt communications, satellite-based GPS, flaring up magnetic field around electricity power stations or transmitters. A partial tech blackout is likely to disrupt the Internet-based communications, they added.

Effects on Earth?

Since the severity has been classified as low by NOAA, it may cause voltage fluctuations in electricity supply or even cause power failures for now. However, the US Space Weather Prediction Center (SWPC) has issued a storm alert on Sunday and Monday stating that the solar storm could cause a “high stream of activity” that is characteristic to any G1-class storm. The gigantic coronal hole in the sun’s surface was captured today by NASA’s Solar Dynamics Observatory (SDO), said SWPC.

“G1 (Minor) geomagnetic storm watches have been issued for 06 and 07 May 2018 due to the anticipated effects of a negative polarity coronal hole high speed stream… Aurora may be visible at high latitudes, that is, northern tier of the US such as northern Michigan and Maine,” said SWPC in a statement.

Meanwhile, conspiracy theorists woke up to the situation to claim that these disruptions are due to the effect of an approaching Nibiru planet which is lurking in the vicinity of our solar system. David Meade, its proponent, has repeated that the next seven years will witness tribulation with many more calamities. NASA has denied these claims as Internet Hoax, though.

50-Year-Cycle?

 

Researchers have long announced that a storm is likely to come and the most intense solar flare may reach earth in maximum fifty years. It is not sure whether the Sunday storm was the one or not.

Mausumi Dikpati of the National Center for Atmospheric Research (NCAR), who’s been working on these storms for decades, predicted that the next solar storm will be a stronger one. “The next sunspot cycle will be 30% to 50% stronger than the previous one,” she said a few years ago. It can produce a burst of solar activity second only to the historic Solar Max of 1958.

Earlier, such intense solar storms had been observed in 1805 and 1958 but with no mobiles and magnetic power lines, the disruption was not detectable as clearly as it would today when auroras and cell technology will showcase the real impact.

According to solar physicist David Hathaway of the National Space Science and Technology Center (NSSTC), a typical sunspot exists for just a few weeks. When it decays, it leaves behind a ‘corpse’ of weak magnetic fields.

Whether the big Doomsday is Sunday or not will be known sooner. For now, a storm is coming and how big will it be remains a major question.

Japan scientist finds 1 out of 15 exoplanets habitable

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Japanese astronomer team led by Teruyuki Hirano of Tokyo Institute of Technology has validated 15 exoplanets orbiting red dwarf systems and found one of them highly akin to Earth and habitable. It could be of particular interest as researchers describe it as a ‘super-Earth’, which could harbour liquid water, and potential alien life.

One of them, K2-155 located around 200 light years away from Earth, has three transiting super-Earths, which are slightly bigger than ours and interestingly the outermost planet, K2-155d, with a radius 1.6 times that of Earth, could be within the host star’s habitable zone, they said.

The findings, published in The Astronomical Journal, are based on data from NASA Kepler spacecraft’s second mission, K2, and other data from the ground-based telescopes, including the Subaru Telescope in Hawaii and the Nordic Optical Telescope (NOT) in Spain.

The Japanese researchers found that K2-155d could potentially have liquid water on its surface based on 3D climate simulations. Hirano said: “In our simulations, the atmosphere and the composition of the planet were assumed to be Earth-like, and there’s no guarantee that this is the case.”

A key outcome from the current studies was that planets orbiting red dwarfs may have remarkably similar characteristics to planets orbiting solar-type stars.

“It’s important to note that the number of planets around red dwarfs is much smaller than the number around solar-type stars,” says Hirano. “Red dwarf systems, especially coolest red dwarfs, are just beginning to be investigated, so they are very exciting targets for future exoplanet research.”

While the radius gap of planets around solar-type stars has been reported previously, this is the first time that researchers have shown a similar gap in planets around red dwarfs. “This is a unique finding, and many theoretical astronomers are now investigating what causes this gap,” says Hirano.

He adds that the most likely explanation for the lack of large planets in the proximity of host stars is photoevaporation, which can strip away the envelope of the planetary atmosphere.

The researchers also investigated the relationship between planet radius and metallicity of the host star. “Large planets are only discovered around metal-rich stars,” Hirano says, “and what we found was consistent with our predictions. The few planets with a radius about three times that of Earth were found orbiting the most metal-rich red dwarfs.”

The studies were conducted as part of the KESPRINT collaboration, a group formed by the merger of KEST (Kepler Exoplanet Science Team) and ESPRINT (Equipo de Seguimiento de Planetas Rocosos Intepretando sus Transitos) in 2016.

With the planned launch of NASA’s Transiting Exoplanet Survey Satellite (TESS) in April 2018, Hirano is hopeful that even more planets will be discovered. “TESS is expected to find many candidate planets around bright stars closer to Earth,” he says. “This will greatly facilitate follow-up observations, including investigation of planetary atmospheres and determining the precise orbit of the planets,” he said.

Figure 1. Results of 3D global climate simulations for K2-155d

Surface temperatures were plotted as a function of insolation flux (the amount of incoming stellar radiation) estimated at 1.67±0.38. When the insolation exceeds 1.5, a so-called runaway greenhouse effect occurs, signaling a cut-off point for life-friendly temperatures. If the insolation is under 1.5, the surface temperature is more likely to be moderate.

Figure 2. Distribution of planet sizes

Histogram of planet radius for the validated and well-characterized transiting planets around red dwarfs: The number counts for mid-to-late red dwarfs (those with a surface temperature of under 3,500 K) are shown above those for early red dwarfs (those with a surface temperature of around 3,500–4,000 K). The results show a “radius gap”, or a dip in the number of stars with a radius between 1.5–2.0 times that of Earth.

42 Indian Satellites Orbiting in Outer Space: Minister

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At present, there are 42 Indian satellites operational in orbit, 15 of them for communication, 4 for meteorological observations, 14 for earth observations, 7 for navigation and 2 for space science purposes.

During FY 2016-17, the total revenue accrued from communication satellites through leasing of INSAT/ GSAT transponders is Rs. 746.68 crore.

With respect to earth observation satellites, the annual income from sale of remote sensing satellite data is Rs. 25.17 crores.

The data and value added services derived from earth observation, meteorological, communication & navigation satellites are used to support various applications like resource monitoring, weather forecasting, disaster management, location based services, including societal applications, informed Union Minister of State for Atomic Energy and Space, Dr Jitendra Singh in a written reply to a question in Rajya Sabha on Wednesday, July 20, 2017.

In current calendar year of 2017, Indian Space Research Organisation (ISRO) has launched 104 satellites, in a single launch, onboard PSLV-C37 on February 15, 2017 and 31 satellites, in a single launch, on-board PSLV-C38 on June 23, 2017, he had informed the Lok Sabha earlier on July 19, 2017.

These satellites include – Two Indian Cartosat-2 series satellites, two Indian Nano-Satellites, one Nano satellite from Indian University and 130 foreign satellites from 19 countries viz. Austria, Belgium, Chile, Czech Republic, France, Finland, Germany, Italy, Israel, Japan, Kazakhstan, Latvia, Lithuania, Slovakia, Switzerland, The Netherlands, UAE, UK and USA.

 

Using Einstein’s Theory, Brightest Galaxy 10000 Million Light Years Away Discovered

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Using Albert Einstein’s gravitational lensing theory, scientists have discovered a galaxy at about 10,000 million light years away but thousand times brighter than the nearest Milky Way.

Anastasio Diaz-Sanches from Polytechnic University of Cartagena (UPCT) in Spain used gravitational lensing phenomenon found by Einstein to magnify the apparent image of the original object.

“Thanks to the gravitational lens” explained Sánchez, “produced by a cluster of galaxies between ourselves and the source, which acts as if it was a telescope, the galaxy appears 11 times bigger and brighter than it really is.” It appears as several images on an arc centred on the densest part of the cluster, known as ‘Einstein Ring’.

To measure it they used the Gran Telescopio Canarias at the Roque de los Muchachos Observatory in Garafía, La Palma. The advantage of this type of amplification is that it does not distort the spectral properties of the light, enabling the study of very distant objects as if they were much nearer.

The galaxy is forming stars at a rate of 1,000 solar masses per year, compared to the Milky Way which is forming stars at a rate of some twice a solar mass per year. Susana Iglesias-Groth, co-author of the research said, “This type of objects harbour the most powerful star forming regions known in the universe. The next step will be to study their molecular content”.

The research findings were published in the Astrophysical Journal Letters.

The fact that the galaxy is so bright, its light is gravitationally amplifed, and has multiple images allows us to look into its internal properties, which would otherwise not be possible with such distant galaxies.

“In the future we will be able to make more detailed studies of its star formation using interferometers such ast the Northern Extended Millimeter Array (NOEMA/IRAM),in France, and the Atacama Large Millimeter Array (ALMA), in Chile,” said IAC researcher Helmut Dannerbauer, who is another contributor to the paper.

‘Star Trek’ Fiction Comes True, China Succeeds in Quantum Teleportation

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Chinese scientists have achieved a breakthrough in much-awaited quantum teleportation when they successfully teleported photons to an orbiting satellite 300 miles above, paving the way for a future unhackable quantum Internet.

In Star trek, Scotty beams up crew to distant locations anytime and in the latest experiment, Chinese researchers were able to beam photons from a ground station in Ngari, Tibet to their Micius satellite, which is orbiting 300 miles above in the sky.

“Space-scale teleportation can be realised and is expected to play a key role in the future distributed quantum internet,” said the team of authors, led by Professor Chao-Yang Lu from the University of Science and Technology of China.

Explaining the process, their research paper said, “An arbitrary unknown quantum state cannot be precisely measured or perfectly replicated. However, quantum teleportation allows faithful transfer of unknown quantum states from one object to another over long distance, without physical travelling of the object itself.”

Teleportation also enhances capabilities of unhackable large-scale quantum networks and distributed quantum computation. In previous experiments, photons were lost in optical fibres or space channels after about 100-km distance.

Chinese experiment was based on satellite platform and space-based link, which can conveniently connect two remote points on the Earth with greatly reduced channel loss because most of the photons’ propagation path is in empty space, they said.

The team was able to teleport independent single-photon qubits from a ground observatory to a low Earth orbit satellite – through an up-link channel – with a distance of up to 1,400 km. To optimize the link efficiency and overcome the atmospheric turbulence in the up-link, a series of techniques are developed, including a compact ultra-bright source of multi-photon entanglement, narrow beam divergence, high-bandwidth and high-accuracy acquiring, pointing, and tracking (APT).

“We demonstrate successful quantum teleportation for six input states in mutually unbiased bases with an average fidelity of 0.80+/-0.01, well above the classical limit. This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet,” they said.

NASA’s Juno to Fly Directly Over Jupiter’s Mysterious Red Spot Now

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NASA’s Juno spacecraft is all set for another manoeuvre on July 10, flying directly over Jupiter’s Great Red Spot, the gas giant’s iconic, 10,000-mile-wide (16,000-kilometer-wide) storm.

This meanoeuvre will be humanity’s first close-up view of the gigantic storm being monitored since 1830 and possibly existing for more than 350 years on Jupiter, making it mysterious and puzzling.

“Jupiter’s mysterious Great Red Spot is probably the best-known feature of Jupiter,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “This monumental storm has raged on the solar system’s biggest planet for centuries. Now, Juno and her cloud-penetrating science instruments will dive in to see how deep the roots of this storm go, and help us understand how this giant storm works and what makes it so special,” said a NASA report.

The July 10 flyby will Juno’s sixth on to the gas giant’s mysterious cloud tops. Since Juno’s perijove is on Monday, July 10, at 6:55 pm PDT (9:55 pm EDT), Juno will be about 2,200 miles (3,500 kilometers) above the planet’s cloud tops.

In its closest reach lasting for 11 minutes and 33 seconds, Juno will cover another 24,713 miles (39,771 kilometers) and will be directly above the coiling crimson cloud tops of Jupiter’s Great Red Spot, said NASA. The spacecraft will bee about 5,600 miles (9,000 kilometers) above the Giant Red Spot clouds and all its 8 instruments and its camera JunoCam, will be directly on the storm during the flyby.

“The success of science collection at Jupiter is a testament to the dedication, creativity and technical abilities of the NASA-Juno team,” said Rick Nybakken, project manager for Juno from NASA’s Jet Propulsion Laboratory in Pasadena, California. “Each new orbit brings us closer to the heart of Jupiter’s radiation belt, but so far the spacecraft has weathered the storm of electrons surrounding Jupiter better than we could have ever imagined.”

As US is celebrating its Independence Day on July 4, Juno will have logged exactly one year in Jupiter orbit.

 

Cassini Takes Plunge Into Saturn, Scientists Cross-Fingered

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In its line up for final plunge into Saturn’s atmosphere, Cassini has once again taken a proximal plunge into the surface of Saturn on June 29, 2017. The final plunge is scheduled for mid-September.

The Cosmic Dust Analyzer’s (CDA) science team, in Germany adjusted the instrument’s settings this week based on experience in recent “proximal” passages between Saturn’s rings and atmosphere. They have created a string of 39 commands that would set the instrument to make the best possible observations during the next proximal plunge. Now the instrument’s data-collection rate has been adjusted to 4 kilobits per second, thus making sure all ring-particle impacts would be sensed.

Here is a week-long update previous to the plunge:

Wednesday, June 21 (DOY 172)

Writers, bloggers, photographers, educators, students, artists and others who use social media to engage specific audiences are encouraged to apply for special access to Cassini’s Grand Finale event in mid-September.

Thursday, June 22 (DOY 173)

The Composite Infrared Spectrometer (CIRS) turned and looked at Saturn’s large icy moon Dione for 3.5 hours today. The Imaging Science Subsystem (ISS), the Visible and Infrared Mapping Spectrometer (VIMS), and the Ultraviolet Imaging Spectrograph (UVIS) – all the other Optical Remote-Sensing (ORS) instruments – rode along to make observations as well. CIRS’s goal was to measure Dione’s surface emissivity at thermal-infrared wavelengths, which hold clues to the composition and structure of that moon’s regolith.

Friday, June 23 (DOY 174)

Beginning late today, the spacecraft trained its High-Gain Antenna dish on the distant Earth. It then accurately tracked our planet for a total of 28 hours. Accordingly, the Radio Science Subsystem (RSS) team had Cassini power on its S-band (2 GHz) and Ka-band (32 GHz) radio transmitters, which directed their beams of energy out the HGA along with the main communications beam at X-band (8 GHz).

The result was a high-precision measurement of Saturn’s gravitation, which will be analyzed to reveal deviations from spherical symmetry.

Saturday, June 24 (DOY 175)

CIRS observed the dark side of Saturn’s A ring at far-infrared wavelengths for five hours today, with the other ORS instruments riding along. In addition to studying ring-particle compositions, the observation was part of a campaign to compare the spectral properties of ices among different regions of Saturn’s rings and icy moons.

Cassini and Titan happened to come close to one another today, to a distance about the same as that from Earth to our own Moon.

Sunday, June 25 (DOY 176)

This week’s Titan observing wrapped up with its final 4.3 hours devoted to observing clouds on the planet-like moon; VIMS rode along.

Monday, June 26 (DOY 177)

ISS turned and spent 7.7 hours observing Saturn’s irregular moon Bebhionn, an object of about six kilometers diameter, which orbits Saturn in an inclined ellipse that reaches as far as 25.1 million km from the planet. It might have a binary or contact-binary nature. Bebhionn was named after the goddess of birth in early Irish mythology.

The flight team held a Command Approval Meeting fine-tuning commands with consent from representatives from each of the affected spacecraft subsystems and instruments.

Tuesday, June 27 (DOY 178)

UVIS observed. Ten minutes after the Deep Space Network (DSN) station in Australia acquired Cassini’s downlink, its 18-kilowatt transmitter was turned on, and comands were sent. After a round-trip of 2 hours 31 minutes, telemetry confirmed that the commands had been received and were ready to take effect right before Cassini’s eleventh proximal plunge on June 29.

A total of 58 individual commands were uplinked, and about 1,625 megabytes of science and engineering telemetry data were downlinked and captured at rates as high as 142,201 bits per second.

Wrap up:

Cassini is executing its set of 22 Grand Finale Proximal orbits, which have a period of 6.5 days, in a plane inclined 61.9 degrees from the planet’s equatorial plane. Each orbit stretches out to an apoapsis altitude of about 1,272,000 km from Saturn, where the spacecraft’s planet-relative speed is around 6,000 km/hr. At periapsis, the distance shrinks to about 2,500 km above Saturn’s visible atmosphere on the planet’s total 120,660 km in diameter with a speed of 123,000 km/hr.

ISRO Launches PSLV-C36 Remote Sensing Satellite

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In its 38th flight (PSLV-C36), ISRO’s Polar Satellite Launch Vehicle successfully launched the 1,235 kg RESOURCESAT-2A Satellite on Wednesday morning (December 07, 2016) from the Satish Dhawan Space Centre SHAR, Sriharikota.

After PSLV-C36 lift-off at 10:25 am IST from the First Launch Pad with the ignition of the first stage, the subsequent important flight events, namely, strap-on ignitions and separations, first stage separation, second stage ignition, payload fairing separation, second stage separation, third stage ignition and separation, fourth stage ignition and cut-off, took place as planned.

After a flight of 17 minutes 05 seconds, the vehicle achieved a polar Sun Synchronous Orbit of 824 km height inclined at an angle of 98.725 degree to the equator (very close to the intended orbit) and 47 seconds later, RESOURCESAT-2A was separated from the PSLV fourth stage.

After separation, the two solar arrays of RESOURCESAT-2A deployed automatically and ISRO’s Telemetry, Tracking and Command Network (ISTRAC) at Bangalore took over the control of the satellite. In the coming days, the satellite will be brought to its final operational configuration following which it will begin to provide imagery from its three cameras. The data sent by RESOURCESAT-2A will be useful for agricultural applications like crop area and crop production estimation, drought monitoring, soil mapping, cropping system analysis and farm advisories generation.

Like its predecessors RESOURCESAT-1 and 2, RESOURCESAT-2A has a unique 3-Tier imaging system with Advanced Wide Field Sensor (AWiFS), Linear Imaging Self Scanner-3 (LISS-3) and Linear Imaging Self Scanner-4 (LISS-4) cameras. The AWiFS provides images with a sampling of 56 metres, a swath of 740 km and a revisit of 5 days whereas the LISS-3 provides 23.5 metre sampled images with 141 km swath and a repitivity of 24 days. LISS-4 provides 5.8 metre sampled images with 70 km swath and a revisit of 5 days.

"With today’s launch, the PSLV has yet again demonstrated its reliability," said ISRO in a statement. The total number of satellites launched by India’s workhorse launch vehicle PSLV including today’s RESOURCESAT-2A has now reached 122, of which 43 are Indian and the remaining 79 are from abroad.

Indian Origin Scientist Makes it to 36 NASA Fellows of 2016 Final List

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NASA has selected 36 fellows for its prestigious Einstein, Hubble and Sagan fellowships, including one Indian called Dheeraj Pasham from Massachusetts Institute of Technology, Cambridge, who will conduct research on “Quest for the Elusive Intermediate-mass Black Holes”.

 

Dheeraj Pasham

Dheeraj Pasham (“DJ”) received his Bachelor’s degree in Aerospace Engineering from the Indian Institute of Technology Bombay in 2004. He obtained his Ph.D. from the University of Maryland in College Park (2014) where he focused on X-ray timing studies to understand the nature of ultraluminous X-ray sources in order to answer the question of whether they host stellar-mass or intermediate-mass black holes.

As an Einstein fellow at MIT, he plans to apply and extend his expertise in time series analysis to (1) identify and weigh intermediate-mass black holes, and (2) address the many open questions concerning the tidal disruption of stars by supermassive and intermediate-mass black holes.

See full bio of other selected scientists here.

Each post-doctoral fellowship provides three years of support to awardees to pursue independent research in astronomy and astrophysics. The new fellows will begin their programs in the fall of 2016 at a host university or research center of their choosing in the United States.

“The selected fellows are some of the brightest, rising stars in the field of astronomy and astrophysics,” said Paul Hertz, director of Astrophysics at NASA Headquarters, Washington. “We look forward to the exciting discoveries they make that further our understanding of the universe.”