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Astronomy & Space

See the waning Moon meet Jupiter and Saturn at daybreak, 27–29 March – Astronomy Now

March 26, 2019 • By

Observers within the British Isles and Western Europe wishing to see the waning Moon meet each Jupiter and Saturn ought to search unobstructed view of the horizon from southeast by south some 45 minutes earlier than dawn from 27–29 March 2019. The Moon occults Saturn as seen from South Africa round nautical daybreak on Friday, 29 March. AN animation by Ade Ashford.

Now that the waning Moon is rising after midnight, deep-sky observers within the UK and Western Europe can rejoice on the return of darkish night skies for looking down all kinds of extragalactic deep-sky objects (some described right here). For lunar and planetary lovers, nevertheless, the one naked-eye planet of the night sky is distant and tiny Mars within the constellation of Taurus. However when you’re ready to be an early riser, the daybreak sky is the place you’ll discover two of the photo voltaic system’s heavyweights, Jupiter and Saturn.

Jupiter, the biggest planet, at present lies in Ophiuchus, the unofficial 13th zodiacal constellation. Presently shining at magnitude -2.2 and due to this fact the brightest object within the daybreak sky apart from the Moon, Jupiter could be discovered low within the southern sky on the onset of civil twilight some 35 minutes earlier than dawn within the UK.

On the morning of Wednesday, 27 March round 5am GMT you will discover Jupiter simply 1½ levels to the decrease proper of the 21-day-old waning gibbous Moon. Therefore the Moon and planet will simply slot in the identical discipline of view of binoculars and telescopes magnifying 30× or much less. In increased magnification devices you’ll see that Jupiter seems to have solely two Galilean moons at the moment – Callisto to the east and Ganymede to the appropriate. (Io is behind Jupiter and Europa is eclipsed by the planet’s shadow).

Two mornings later, it’s magnitude +0.6 Saturn’s flip to get considerably nearer to the waning Moon. If you happen to look very low within the south-southeast at 5am GMT on Friday, 29 March you possibly can see the 23-day-old lunar crescent simply two Moon widths beneath the ringed planet. Saturn’s largest and brightest moon, magnitude +9 Titan, occurs to be near biggest elongation this explicit morning, some 4⅓ ring diameters east of its father or mother planet.

As seen from extra southerly latitudes, particularly South Africa, the Moon truly occults (passes in entrance of) Saturn round nautical daybreak on Friday, 29 March.


Astronomy & Space

Asteroid Bennu surprises with rocky floor and exercise – Astronomy Now

March 24, 2019 • By
A high-resolution view from the OSIRIS-REx spacecraft exhibiting the rockier-than-expected floor of the asteroid Bennu, one in every of many surprises for the reason that probe slipped into orbit across the tiny physique final December. Picture: NASA/Goddard/College of Arizona/Lockheed Martin

NASA’s OSIRIS-REx spacecraft, intently learning the asteroid Bennu, has chanced on one shock after one other since slipping into orbit across the tiny physique three December. Within the pattern return mission’s most dramatic discovery thus far, OSIRIS-REx has monitored a minimum of 11 “ejection events” by which rocky streams of particles could be seen spewing into house, a few of the fragments transferring quick sufficient to flee the asteroid’s minuscule gravity.

“Some of those slow-moving particles have been observed over periods of at least a week, and they appear to be trapped in the asteroid’s gravity field and are ending up in orbit around Bennu,” Dante Lauretta, the OSIRIS-REx principal investigator, informed reporters on the Lunar and Planetary Science Convention in Woodlands, Texas.

“So it’s creating its own set of natural satellites,” he mentioned. “And then some of them have been observed to fall back onto the surface. Basically, it looks like Bennu has a continuous population of particles raining down on it from discrete ejection events across its surface.”

Cautious evaluation signifies the fragments don’t pose a risk to OSIRIS-REx, however they might complicate navigation because the spacecraft slowly orbits and descends to the floor to gather soil samples subsequent yr.

In a major discovery, OSIRIS-REx’s cameras have noticed a number of ejection occasions by which particles (heart and higher proper) are spewing away from Bennu. Picture: NASA/Goddard/College of Arizona/Lockheed Martin

One other complication? Bennu is far rockier than anticipated based mostly on radar observations from Earth, and discovering a comparatively clean space the place the probe’s touch-and-go pattern acquisition system collector, or TAGSAM, can work correctly might be tougher than anticipated.

Mission planners initially anticipated deciding on a pattern assortment space greater than 160 ft throughout, however they now might want to put TAGSAM down on a a lot smaller goal.

Wealthy Burns, the OSIRIS-REx challenge supervisor at NASA’s Goddard House Flight Centre in Greenbelt, Maryland, mentioned the spacecraft’s navigation system is extra exact in flight than anticipated and “we feel confident our systems and our teams are up to the task of tagging to a sample collection site of much smaller than was previously envisioned.”

“You can imagine you’re just shooting at a dart board, just trying to hit the board,” he mentioned. “Well now, we’re going to try to hit the centre of the bull’s eye. We feel like the performance of the system and the team supports that notion, and we are working actively to make that happen.”

Bennu was found in 1999 and chosen as a goal for OSIRIS-REx as a result of it’s comparatively near Earth and rotating slowly sufficient for the spacecraft to “match rates” for the pattern acquisition. It is also wealthy in carbon compounds and attainable natural precursors of life because it’s identified on Earth.

OSIRIS-REx was launched in September 2016. It would spend greater than a yr mapping Bennu in extraordinary element earlier than the science group selects a main and backup sampling space.

If all goes nicely, the spacecraft will descend to only above the floor in the summertime of 2020, briefly urgent TAGSAM onto the soil. The pattern collector, mounted on the top of a robotic arm and formed considerably like a cake pan, will hearth nitrogen gasoline to fire up the soil instantly beneath, capturing mud and small rocks kicked up from the floor.

The samples then might be saved in an aerodynamic return car for return to Earth in 2023.

Asteroid Bennu is formed considerably like a baby’s toy prime. It’s a “rubble pile” asteroid, one of many few in its class identified to be actively ejecting materials from its floor. Picture: NASA/Goddard/College of Arizona/Lockheed Martin

“Bennu does not contain the extensive patches of fine-grained regolith according to which we designed the mission,” Lauretta wrote in a letter to the journal Nature this week. “Nevertheless, we recognized a number of areas, starting from 5 to 20 meters (16 to 65 ft) in extent, that seem comparatively freed from spacecraft hazards and have textures suggestive of plentiful nice particles.

“We will perform a thorough safety assessment of the asteroid environment and all potential sample sites before committing the spacecraft to descent to the surface. Although we face a reality that differs from many of our predictions, we will attempt to sample Bennu before the spacecraft departs for Earth.”


Astronomy & Space

Rumors of a quasar’s demise could have been untimely – Astronomy Now

March 22, 2019 • By
A quasar nicknames the Teacup includes a “handle” of optical and X-ray mild surrounding an enormous bubble of sizzling gasoline blown away from a supermassive black gap on the coronary heart of the galaxy. Picture: X-ray: NASA/CXC/Univ. of Cambridge/G. Lansbury et al; Optical: NASA/STScI/W. Keel et al.

A voracious supermassive black gap on the heart of a galaxy 1.1 billion mild years away is energising an excellent quasar, sucking in large quantities of gasoline and dirt which can be accelerated to excessive velocities, inflicting the doomed materials to warmth up and within the course of emit extra radiation than all the celebs within the galaxy mixed.

The galaxy, formally generally known as SDSS 1430+1339, seems to be considerably like a cosmic teacup because of a curved “handle” of optical and X-ray mild extending some 30,000 mild years from the black gap that surrounds an enormous bubble-like void. The bubble presumably fashioned after a number of eruptions on the core of the galaxy. Radio emissions present the presence of the same bubble-like construction on the alternative aspect of the galaxy’s core.

Earlier optical observations discovered that atoms within the teacup’s deal with had been ionised by robust radiation from the supermassive black gap prior to now. The quantity of radiation required to do this, in comparison with emissions from the core, indicated the quasar’s radiation had dropped by an element of 50 to 600 over the previous 40,000 to 100,000 years.

The evaluation led some astronomers to conclude the quasar was, in a way, dying.

However new remark’s by NASA’s Chandra X-ray Observatory and the European Area Company’s XMM-Newton point out the quasar is obscured by thick clouds of gasoline, implying it seemingly is producing way more high-energy radiation than indicated by optical observations alone. As such, the dimming famous earlier could also be nearer to an element of 25 over the previous 100,000 years.

The Chandra observations additionally present proof for higher-temperature gasoline contained in the bubble marked by the teacup’s deal with. That will point out the bubble was fashioned by a wind of fabric blowing away from the black gap.


Astronomy & Space

Ultima Thule solutions – and raises – questions on early photo voltaic system – Astronomy Now

March 20, 2019 • By

 

Ultima Thule, a bilobate “contact binary” within the Kuiper Belt a billion miles previous Pluto, is offering new insights into planetary formation. Picture: NASA/Johns Hopkins College Utilized Physics Laboratory/Southwest Analysis Institute

The farthest object ever explored is slowly revealing its secrets and techniques, as scientists piece collectively the puzzles of Ultima Thule – the Kuiper Belt object NASA’s New Horizons spacecraft flew previous on New Yr’s Day, 4 billion miles from Earth.

Analysing the info New Horizons has been sending residence because the flyby of Ultima Thule (formally named 2014 MU69), mission scientists are studying extra concerning the growth, geology and composition of this historic relic of photo voltaic system formation. The staff mentioned these findings (18 March) on the 50th Lunar and Planetary Science Convention in The Woodlands, Texas.

Ultima Thule is the primary unquestionably primordial contact binary ever explored. Strategy footage of Ultima Thule hinted at a wierd, snowman-like form for the binary, however additional evaluation of photos, taken close to closest strategy – New Horizons got here to inside simply 2,200 miles (3,500 kilometres) – have uncovered simply how uncommon the KBO’s form actually is. At 22 miles (35 kilometres) lengthy, Ultima Thule consists of a big, flat lobe (nicknamed “Ultima”) linked to a smaller, rounder lobe (nicknamed “Thule”).

This unusual form is the most important shock, to this point, of the flyby. “We’ve never seen anything like this anywhere in the solar system,” mentioned New Horizons principal investigator Alan Stern, of the Southwest Analysis Institute, Boulder, Colorado. “It is sending the planetary science community back to the drawing board to understand how planetesimals – the building blocks of the planets – form.”

Initially regarded as made up of two roughly spherical our bodies, Ultima Thule is now recognized to be composed of flatter our bodies that initially have been in orbit round one another. They misplaced vitality by way of satellites, interactions with surrounding gasoline or different close by our bodies and ultimately bumped collectively at about 2 metres per second, or almost 5 mph. Picture: NASA/Johns Hopkins College Utilized Physics Laboratory/Southwest Analysis Institute

As a result of it’s so nicely preserved, Ultima Thule is providing our clearest look again to the period of planetesimal accretion and the earliest phases of planetary formation. Apparently Ultima Thule’s two lobes as soon as orbited one another, like many so-called binary worlds within the Kuiper Belt, till one thing introduced them collectively in a “gentle” merger.

“This fits with general ideas of the beginning of our solar system,” mentioned William McKinnon, a New Horizons co-investigator from Washington College in St. Louis. “Much of the orbital momentum of the Ultima Thule binary must have been drained away for them to come together like this. But we don’t know yet what processes were most important in making that happen.”

That merger might have left its mark on the floor. The “neck” connecting Ultima and Thule is reworked, and will point out shearing because the lobes mixed, mentioned Kirby Runyon, a New Horizons science staff member from the Johns Hopkins Utilized Physics Laboratory in Laurel, Maryland.

Runyon and fellow staff geologists are describing and attempting to know Ultima Thule’s many floor options, from shiny spots and patches, to hills and troughs, to craters and pits. The craters, whereas at first look appear like influence craters, might produce other origins. Some could also be pit craters, the place materials drains into underground cracks, or a results of sublimation, the place ice went instantly from stable to gasoline and left pits instead. The biggest melancholy is a 5-mile-wide (8-kilometre-wide) characteristic the staff has nicknamed Maryland crater. It might be an influence crater, or it might have fashioned in one of many different above-mentioned methods.

“We have our work cut out to understand Ultima Thule’s geology, that is for sure,” Runyon mentioned.

Ultima Thule is deeply reddish in color as seen in photos combining observations from two cameras aboard the New Horizons spacecraft. Picture: NASA/Johns Hopkins College Utilized Physics Laboratory/Southwest Analysis Institute

In color and composition, New Horizons knowledge revealed that Ultima Thule resembles many different objects present in its area of the Kuiper Belt. According to pre-flyby observations from the Hubble Telescope, Ultima Thule could be very crimson – redder even than Pluto, which New Horizons flew previous on the interior fringe of the Kuiper Belt in 2015 – and about the identical color as many different so-called “cold classical” KBOs.

New Horizons scientists have additionally seen proof for methanol, water ice and natural molecules on the floor. “The spectrum of Ultima Thule is similar to some of the most extreme objects we’ve seen in the outer solar system,” mentioned Silvia Protopapa, a New Horizons co-investigator from SwRI. “So New Horizons is giving us an incredible opportunity to study one of these bodies up close.”


Astronomy & Space

Shattering an in-bound asteroid could also be harder than thought – Astronomy Now

March 18, 2019 • By
These frames from a brand new laptop simulation present how fragments from an impacted asteroid would re-accumulate after a collision because of the gravity of its broken however still-intact core. A brand new research exhibits massive asteroids could also be more durable to interrupt aside than beforehand thought. Charles El Mir/Johns Hopkins College

Within the motion pictures “Deep Impact” and “Armageddon,” heroic astronauts plant nuclear bombs to explode big asteroids heading towards Earth. Primarily based on new laptop modelling, which may be harder than initially thought.

“We used to believe that the larger the object, the more easily it would break, because bigger objects are more likely to have flaws,” mentioned Charles El Mir, a latest Ph.D graduate from the Johns Hopkins College’s Division of Mechanical Engineering. “Our findings, however, show that asteroids are stronger than we used to think and require more energy to be completely shattered.”

Within the early 2000s, a special workforce of researchers modelled what would occur if an asteroid 1 kilometre (0.62 miles) in diameter crashed head on right into a 25-kilometre-wide (15.5-mile) asteroid at a velocity of 5 kilometres per second (11,000 mph). The outcomes indicated the bigger asteroid could be utterly shattered and blown aside.

El Mir and Ok.T. Ramesh, director of the Hopkins Excessive Supplies Institute, together with Derek Richardson, an astronomer on the College of Maryland, plugged the identical numbers into a brand new laptop mannequin that features extra detailed, smaller-scale processes that extra precisely mirror how cracks propagate.

The simulation thought of the processes at work within the first fractions of a second after an influence after which the longer-timescale results of gravity on the fragments blown away from the floor and their re-accumulation properly after the influence. The mannequin signifies the complete asteroid just isn’t shattered. A broken core stays that exerts a agency pull on the fragments blasted away within the preliminary influence.

As an alternative of leaving a “rubble pile” in its wake, the impacted asteroid possible would stay a formidable physique as a result of it didn’t utterly crack aside.

“It may sound like science fiction, but a great deal of research considers asteroid collisions,” mentioned El Mir. “For example, if there’s an asteroid coming at Earth, are we better off breaking it into small pieces, or nudging it to go a different direction? And if the latter, how much force should we hit it with to move it away without causing it to break? These are actual questions under consideration.”

A paper detailing the outcomes of the research might be revealed within the March 15 challenge of Icarus.


Astronomy & Space

Milky Method ideas the scales at 1.5 trillion photo voltaic plenty – Astronomy Now

March 16, 2019 • By
The disc of the Milky Method above ESO’s Paranal Observatory in Chile. Picture: ESO/P. Horálek

The Milky Method is a reasonably regular spiral galaxy made up of 200 billion to 400 billion suns orbiting a nucleus that comprises a 4-million-solar-mass black gap. However all of that materials contributes only a few p.c of the galaxy’s whole mass. The remainder is made up of darkish matter, the mysterious, unseen substance that gives the gravitational glue holding the galaxy collectively.

Utilizing exact observations of distant globular clusters by the European House Company’s Gaia spacecraft and NASA’s Hubble House Telescope, astronomers have provide you with probably the most correct measurement but of the Milky Method’s whole mass. It comprises about 1.5 trillion occasions the mass of Earth’s Solar.

“We want to know the mass of the Milky Way more accurately so that we can put it into a cosmological context and compare it to simulations of galaxies in the evolving universe,” mentioned Roeland van der Marel of the House Telescope Science Institute. “Not knowing the precise mass of the Milky Way presents a problem for a lot of cosmological questions.”

This illustration exhibits the Milky Method galaxy surrounded by a diffuse halo of stars and historical globular clusters. The motion of such distant clusters exhibits the gravitational affect of unseen darkish matter, permitting astronomers to calculate the whole mass of the galaxy. Picture: NASA, ESA, and A. Feild (STScI)

The lightest galaxies weigh in at a couple of billion photo voltaic plenty whereas the heaviest can tip the scales at some 30 trillion. The Milky Method’s 1.5 trillion photo voltaic plenty is taken into account regular for a galaxy of its brightness.

To provide you with that quantity, Gaia tracked 34 globular clusters at distances as much as 65,000 mild years whereas Hubble zoomed in on a dozen extra distant clusters positioned as much as 130,000 mild years away.

Globular clusters are made up of the oldest recognized stars and are thought to have shaped earlier than the Milky Method’s spiral disc developed. By monitoring how briskly such cluster transfer throughout the sky, astronomers can calculate how a lot matter, darkish or “normal,” have to be current to supply the noticed gravitational acceleration.

“The more massive a galaxy, the faster its clusters move under the pull of its gravity,” mentioned N. Wyn Evans of the College of Cambridge. “Most previous measurements have found the speed at which a cluster is approaching or receding from Earth, that is the velocity along our line of sight. However, we were able to also measure the sideways motion of the clusters, from which the total velocity, and consequently the galactic mass, can be calculated.”


Astronomy & Space

NASA selects 9 groups to check unopened Apollo moon samples

March 14, 2019 • By
Apollo 17 commander Gene Cernan approaches the crew’s lunar rover throughout one among three sample-collection moonwalks in the course of the remaining Apollo mission in 1972. Unopened samples from that flight and two others are being made accessible to 9 analysis groups. Picture: NASA

NASA has chosen 9 analysis groups to analyse pristine samples of lunar soil returned to Earth by the Apollo astronauts and left untouched for the previous 5 many years. The U.S. house company has allotted $eight million for the analysis below the Apollo Subsequent Technology Pattern Evaluation program, or ANGSA.

“When the previous generations did Apollo, they knew that the technology they had in that day was not the technology we would have in this day,” mentioned NASA Administrator Jim Bridenstine. “So they (decided) to preserve samples, because they knew there would be a day when better technology would be able to better assess the history of the moon.”

Bridenstine made the announcement whereas unveiling NASA’s $21.5 billion 2020 finances request from the Trump administration, a finances that helps the company’s plans to return astronauts to the moon by 2028.

“We have nine teams that will be examining nine unopened samples that have come back from the moon,” the administrator mentioned. “We feel like we can do that because there are more lunar samples on the horizon where we’re going to be able to learn more than we’ve ever learned about the moon before. So I’d like to thank the Apollo generation for preserving these samples so that our generation can have this opportunity.”

The samples have been collected in the course of the Apollo 15, 16 and 17 missions. An Apollo 17 pattern, for instance, can be studied by the College of New Mexico’s Institute of Meteoritics, which can obtain about 800 grams (1.eight kilos) of fabric from a core pattern that was sealed in a vacuum container on the floor of the moon.

The group will measure the chemical constituents of the pattern and “prepare us to explore and sample potential resources for future human activities,” mentioned analysis assistant Charles Shearer. “Further, this will be the first analysis of a core through a lunar landslide deposit and will further our understanding of the timing, triggers, and dynamics of these events. The deposit may contain new lunar rocks never sampled before.”

One other pattern can be assessed by Darby Dyar on the Planetary Science Institute.

“This project brings massive state-of-the-art synchrotron and infrared analysis to bear on tiny lunar samples to unlock the secrets of the lunar interior,” mentioned Dyar, a senior scientist at PSI. “We will use state-of-the-art synchrotron technology and a mapping FTIR spectrometer to measure gradients of volatiles ­ hydrogen and oxygen – preserved in lunar glass beads.”

Such beads are shaped by “rapid cooling of droplets from explosive lunar fire fountains, like those seen in Hawaii,” she mentioned. “We will map changes from core to rim that reveal hydrogen and oxygen pressures in the lunar interior and before, during, and after eruption.”

One other analysis group, led by Jessica Barnes, an incoming assistant professor on the College of Arizona’s Lunar and Planetary Laboratory, will search for traces of water in a 110-gram (four ounce) pattern that was collected by the Apollo 17 crew. Like the opposite samples, the soil was moved right into a freezer inside a month of the astronauts’ return.

“The question we want to answer is, are we measuring the true Moon signature? Or are there terrestrial influences that have affected the samples during their storage?” Barnes mentioned. “The beauty of a frozen sample is that it’s been kept curated in a different way from the samples stored at room temperature. We could not do this research without opening the frozen samples.”


Astronomy & Space

Initially not noted of well-known catalogue, M106 blazes in Hubble view

March 12, 2019 • By

Messier 106, also referred to as NGC 4258, is likely one of the most sensible close by galaxies, situated within the constellation Canes Venatici some 20 to 25 million gentle years from Earth. It rivals the Andromeda galaxy in measurement and is a well-known goal for novice astronomers. Found in 1781 by Charles Messier’s assistant, Pierre Méchain, M106 was not initially included in Messier’s well-known catalogue. The galaxy and 6 different objects the pair found had been added to {the catalogue} within the 20th century. This picture combines observations by the Hubble Area Telescope with extra knowledge from novice astronomers Robert Gendler and Jay GaBany.

M106 (NGC 4258) as imaged by the Hubble Area Telescope mixed with knowledge collected by novice astronomers Robert Gendler and Jay GaBany. Picture: Picture: NASA, ESA, the Hubble Heritage Crew (STScI/AURA), and R. Gendler (for the Hubble Heritage Crew). Acknowledgment: J. GaBany

The picture beneath, additionally from the Hubble Area Telescope, consists of the glow of ultraviolet radiation.

Picture: NASA, ESA, and the LEGUS group