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Photo: Asteroid/dwarf planet Hygiea. Credit: ESO/P. Vernazza et al./MISTRAL algorithm (ONERA/CNRS)

A new SPHERE/VLT image of Hygiea, which could be the Solar System’s smallest dwarf planet yet. As an object in the main asteroid belt, Hygiea satisfies right away three of the four requirements to be classified as a dwarf planet: it orbits around the Sun, it is not a moon and, unlike a planet, it has not cleared the neighborhood around its orbit. The final requirement is that it have enough mass that its own gravity pulls it into a roughly spherical shape. This is what VLT observations have now revealed about Hygiea. Credit: ESO/P. Vernazza et al./MISTRAL algorithm (ONERA/CNRS)

Astronomers using ESO’s SPHERE instrument at the Very Large Telescope (VLT) have revealed that the asteroid Hygiea could be classified as a dwarf planet. The object is the fourth largest in the asteroid belt after Ceres, Vesta and Pallas. For the first time, astronomers have observed Hygiea in sufficiently high resolution to study its surface and determine its shape and size. They found that Hygiea is spherical, potentially taking the crown from Ceres as the smallest dwarf planet in the Solar System.

As an object in the main asteroid belt, Hygiea satisfies right away three of the four requirements to be classified as a dwarf planet: it orbits around the Sun, it is not a moon and, unlike a planet, it has not cleared the neighborhood around its orbit. The final requirement is that it has enough mass for its own gravity to pull it into a roughly spherical shape. This is what VLT observations have now revealed about Hygiea.

“Thanks to the unique capability of the SPHERE instrument on the VLT, which is one of the most powerful imaging systems in the world, we could resolve Hygiea’s shape, which turns out to be nearly spherical,” says lead researcher Pierre Vernazza from the Laboratoire d’Astrophysique de Marseille in France. “Thanks to these images, Hygiea may be reclassified as a dwarf planet, so far the smallest in the Solar System.”

The team also used the SPHERE observations to constrain Hygiea’s size, putting its diameter at just over 430 km. Pluto, the most famous of dwarf planets, has a diameter close to 2,400 km, while Ceres is close to 950 km in size.

Surprisingly, the observations also revealed that Hygiea lacks the very large impact crater that scientists expected to see on its surface, the team report in the study published today in Nature Astronomy. Hygiea is the main member of one of the largest asteroid families, with close to 7,000 members that all originated from the same parent body. Astronomers expected the event that led to the formation of this numerous family to have left a large, deep mark on Hygiea.

“This result came as a real surprise as we were expecting the presence of a large impact basin, as is the case on Vesta,” says Vernazza. Although the astronomers observed Hygiea’s surface with a 95 percent coverage, they could only identify two unambiguous craters. “Neither of these two craters could have been caused by the impact that originated the Hygiea family of asteroids whose volume is comparable to that of a 100 km-sized object. They are too small,” explains study co-author Miroslav Brož of the Astronomical Institute of Charles University in Prague, Czech Republic.

The team decided to investigate further. Using numerical simulations, they deduced that Hygiea’s spherical shape and large family of asteroids are likely the result of a major head-on collision with a large projectile of diameter between 75 and 150 km. Their simulations show this violent impact, thought to have occurred about 2 billion years ago, completely shattered the parent body. Once the left-over pieces reassembled, they gave Hygiea its round shape and thousands of companion asteroids. “Such a collision between two large bodies in the asteroid belt is unique in the last 3–4 billion years,” says Pavel Ševeček, a PhD student at the Astronomical Institute of Charles University who also participated in the study.

Studying asteroids in detail has been possible thanks not only to advances in numerical computation, but also to more powerful telescopes. “Thanks to the VLT and the new generation adaptive-optics instrument SPHERE, we are now imaging main belt asteroids with unprecedented resolution, closing the gap between Earth-based and interplanetary mission observations,” Vernazza concludes.

Photo: First Quarter Moon, October 5, 2019.

Our First-Quarter Moon on International Observe the Moon Night, as seen through the Stephens telescope at 9:04 PM EDT. iPhone SE at eyepiece.

 

Our October 5 Open Night was the local event of the International Observe the Moon Night — an annual occurrence meant that encourages observation, appreciation, and understanding of our Moon and its connection to planetary science and exploration. Over the course of the night at Stephens Memorial Observatory some 34 enthusiastic and inquisitive visitors attended and were treated to beautiful and unusual views of Earth’s Moon and planet Saturn.

Unusual? The earliest visitors arrived just as the telescope was set to go … with the sky still bright with twilight. The Moon appeared light and against a power-blue sky background instead of the usual darkness of space. Saturn, invisible to the eye in the bright sky, was also viewed through the telescope in surprising detail.

 

Zooming in on the previous image: That dot in the center of dark-floored crater Alphonsus is its central peak. Over the course of two hours sun rose over that pinnacle making it brighter, and other features began to emerge as we watched. Alphonsus slightly overlaps the crater Ptolemaeus.

After darkness fell enthusiastic visitors took turns looking at a crater and watching a mountain peak become illuminated at sunrise on the Moon! It was a fine night appreciating a sight too often ignored: the wonder of Luna, our nearest neighbor in space.

Graphic: International Observe the Moon Night - 2019

Save the Date! International Observe the Moon Night will take place on October 5th 2019.

Stephens Memorial Observatory of Hiram College will host a Public Night Saturday, October 5, from 7:00 to 9:00 p.m. Earth’s Moon will be featured as our local participation in International Observe the Moon Night — a worldwide appreciation of Earth’s nearest neighbor in space. As an exciting bonus, planet Saturn will float near Moon in our skies and will also be observed. Other objects may also be viewed. Given good viewing conditions the Observatory’s 1901 vintage telescope delivers outstanding detail of the Moon and impressive views of Saturn with its distinctive rings.

An interesting activity any time of year is to make note of the daily changes we see in the phases of Moon. Open the PDF to print a handy guide and journal for lunar observation: Moon-Observation_Journal.

Cloudy skies at the scheduled starting time cancel the event in which case, the observatory will not open. No reservations are required and there is no admission fee for observatory public nights.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.

Updates on programming are available via the Observatory’s Twitter feed: @StephensObs or its website: StephensObservatory.org.

Image: Saturn and Moons

Simulated View: Saturn and Moons, September 14, 2019 at 9:30 PM EDT. Image via Gas Giants

 

UPDATE: Thanks to the 29 visitors, of a wide variety of ages, who came out Saturday night to share the view with us. Early arrivals got good views of Saturn. In the middle of our evening our guests saw Saturn under improving conditions and the rising Moon as it cleared neighboring trees. Those who visited or stayed late viewed the Full Harvest Moon (sometimes through tree leaves). Our Moon, though fascinating to view through our telescope even when Full or nearly so, created huge amounts of natural light “pollution” as it illuminated atmospheric haze and thin clouds — we were unable to see the Great Andromeda Galaxy or the M15 star cluster. The Moon got tangled in trees again as it arced higher into the sky. Our final visitors of the evening, however, were rewarded for their patience with views of the Perseus Double Cluster after it cleared trees. We love trees but not so close to the observatory!

Stephens Memorial Observatory of Hiram College will host a Public Night Saturday, September 14, from 9:00 to 11:00 PM. On the observing list are: Earth’s Moon, Saturn, the Messier 15 star cluster, and, if sky conditions permit, the Andromeda Galaxy, and Perseus Double star cluster. Given good viewing conditions the Observatory’s 1901 vintage telescope delivers outstanding detail of the Moon and impressive views of Saturn and distinctive rings.

Cloudy skies at the scheduled starting time cancel the event in which case, the observatory will not open. No reservations are required and there is no admission fee for observatory public nights.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.

Updates on programming are available via the Observatory’s Twitter feed: @StephensObs or its website: StephensObservatory.org.

Photo: Jupiter as imaged by the Hubble Space Telescope June 27, 2019.

The NASA/ESA Hubble Space Telescope reveals the intricate, detailed beauty of Jupiter’s clouds in this new image taken on June 27, 2019 by Hubble’s Wide Field Camera 3, when the planet was 644 million kilometers from Earth — its closest distance this year. The image features the planet’s trademark Great Red Spot and a more intense color palette in the clouds swirling in the planet’s turbulent atmosphere than seen in previous years. The observations of Jupiter form part of the Outer Planet Atmospheres Legacy (OPAL) program. Credit: NASA, ESA, A. Simon (Goddard Space Flight Center), and M.H. Wong (University of California, Berkeley)  — Click image to view full-size!

 
Among the most striking features in the image are the rich colors of the clouds moving toward the Great Red Spot. This huge anticyclonic storm is roughly the diameter of Earth and is rolling counterclockwise between two bands of clouds that are moving in opposite directions toward it.

As with previous images of Jupiter taken by Hubble, and other observations from telescopes on the ground, the new image confirms that the huge storm which has raged on Jupiter’s surface for at least 150 years continues to shrink. The reason for this is still unknown so Hubble will continue to observe Jupiter in the hope that scientists will be able to solve this stormy riddle. Much smaller storms appear on Jupiter as white or brown ovals that can last as little as a few hours or stretch on for centuries.

The worm-shaped feature located south of the Great Red Spot is a cyclone, a vortex spinning in the opposite direction to that in which the Great Red Spot spins. Researchers have observed cyclones with a wide variety of different appearances across the planet. The two white oval features are anticyclones, similar to small versions of the Great Red Spot.

The Hubble image also highlights Jupiter’s distinct parallel cloud bands. These bands consist of air flowing in opposite directions at various latitudes. They are created by differences in the thickness and height of the ammonia ice clouds; the lighter bands rise higher and have thicker clouds than the darker bands. The different concentrations are kept separate by fast winds which can reach speeds of up to 650 kilometers per hour.

These observations of Jupiter form part of the Outer Planet Atmospheres Legacy (OPAL) program, which began in 2014. This initiative allows Hubble to dedicate time each year to observing the outer planets and provides scientists with access to a collection of maps, which helps them to understand not only the atmospheres of the giant planets in the Solar System, but also the atmosphere of our own planet and of the planets in other planetary systems.

Our 2019 Schedule

StephensAstro —  July 13, 2019 — Leave a comment

Personal, atmospheric, and astronomic factors have played havoc with planning our 2019 public observing schedule. We have, however, finally posted a list of Open Nights for the remainder of the year; it includes a special night and time in December in an effort to show off the Great Orion Nebula — something we’ve not done in years!

To view and/or print a copy of the newly-published schedule, CLICK HERE.

Please note that we may make changes as the season progresses. Of course weather plays a dominant factor and cloudy skies can, and often do, cancel scheduled events. Please check this website and our Twitter feed for updates

Keep looking up!

Photo: August 21, 2017 total solar eclipse. Credits: NASA/Gopalswamy

The corona, a region of the Sun only seen from Earth when the Moon blocks out the Sun’s bright face during total solar eclipses. The corona holds the answers to many of scientists’ outstanding questions about the Sun’s activity and processes. This photo was taken during the total solar eclipse on Aug. 21, 2017. Credits: NASA/Gopalswamy

Be sure to be watching July 2 at 4:00 PM EDT as the total solar eclipse is presented live from Chile, via San Francisco’s Exploratorium. You will not be able to directly see the eclipse from the USA; the total solar eclipse will be visible from a narrow part of the South Pacific Ocean, Chile, and Argentina.

The Exploratorium will be bringing the total solar eclipse to you, no matter where you are. The have sent a team to Chile to broadcast from within the path of totality. Enjoy this full, unnarrated view of the eclipse from the telescopes at the National Science Foundation’s Cerro Tololo Observatory.

Live Telescope View – Not Narrated:
https://www.exploratorium.edu/video/total-solar-eclipse-live-july-2-2019

Live Coverage – Broadcast Style:
https://www.exploratorium.edu/video/total-solar-eclipse-2019-live-coverage

NASA has partnered with the Exploratorium to provide the coverage which it will livestream: three views via separate players on the agency’s website (all times EDT):

  • Live views from telescopes in Vicuna, Chile, without audio, from 3 to 6 PM
  • A one-hour program with live commentary in English, from 4 to 5 PM
  • A one-hour program with live commentary in Spanish, from 4 to 5 PM

NASA Television will also carry the English-language program on its public channel. Both programs will feature updates from NASA’s Parker Solar Probe and Magnetospheric Multiscale missions.

Photo: Gerald ‘Jerry’ Eugene Jackson

Gerald ‘Jerry’ Jackson

GARRETTSVILLE – Gerald ‘Jerry’ Eugene Jackson, 68, of Garrettsville died on June 9, 2019. He was curator/director of Stephens Memorial Observatory of Hiram College from 1997 to 2006.

He was born on March 23, 1951, in Pittsburgh, Pennsylvania to Hugh and Esther (Ostien) Jackson.

He is survived by his wife, Margie Jackson of over 41 years (married September 17, 1977), daughters, Kelly Wood, Heather Stieglitz, Erin Jackson, Katie Atchison, and Molly Jackson; his grandchildren, Jacob, Ryan, and Joshua Wood, and Madeline and Jonah Stieglitz; brothers, Hugh, Bill, and Dale Jackson; sister, Patricia Hrabak; many nieces and nephews and great nieces and nephews; and brothers- and sisters-in-law. Jackson was preceded in death by his parents, Hugh and Esther Jackson.

Jackson retired after 37 years of work from Environmental Growth Chambers in Chagrin Falls. He was a Staff Sergeant in the United States Air Force (1969-1973) and a Vietnam War Veteran. He was a life member of the Veterans of Foreign Wars Post 5067 and 3rd Degree member of the Knights of Columbus Council 11801 in Garrettsville. He was an active member of Saint Ambrose Catholic Church since 1982 where he has served as an usher and council member and enjoyed helping out with events.

Jackson loved astronomy, and he enjoyed teaching his daughters, grandchildren, and the community about the night sky. He was a former long-time member of the Mahoning Valley Astronomical Society having served the club in a number of positions including as president for many years. Jackson was a member of the Antique Telescope Society, and volunteered as director at the Hiram College observatory where he gave tours and maintained the facility’s 1901 vintage telescope. He left the observatory position in 2006.

Jackson together with his wife, Margie, loved to travel. They frequently visited their children and grandchildren from North Carolina to Alaska and took many cruises. Jerry was an avid Pittsburgh sports fan.

Please join Jerry’s family for a memorial visitation on Sunday, June 16, 2019, from 2-4 PM at Mallory-DeHaven-Carlson Funeral Home & Cremation Services; 8382 Center St.; Garrettsville. Mass of Christian burial to be held on Monday, June 17, 2019, at 1 PM at St. Ambrose Catholic Church; 10692 Freedom St.; Garrettsville. Burial to be held on Tuesday, June 18, 2019, at the Ohio Western Reserve National Cemetery; 10175 Rawiga Road; Seville, Ohio 44273.

Online condolences at www.carlsonfuneralhomes.com

This item adapted from a Carlson Funeral Homes obituary published in the Record-Courier, June 13, 2019.

Using the Event Horizon Telescope, scientists obtained an image of the black hole at the center of galaxy M87, outlined by emission from hot gas swirling around it under the influence of strong gravity near its event horizon. Credit: Event Horizon Telescope collaboration et al.

April 10, 2019 — Today, in coordinated press conferences across the globe, Event Horizon Telescope researchers reveal that they have succeeded in unveiling the first direct visual evidence of a supermassive black hole and its shadow. The Event Horizon Telescope (EHT) — a planet-scale array of eight ground-based radio telescopes forged through international collaboration — was designed to capture images of a black hole.

This breakthrough was announced in a series of six papers published in a special issue of The Astrophysical Journal Letters. The image reveals the black hole at the center of Messier 87, a massive galaxy in the nearby Virgo galaxy cluster. This black hole resides 55 million light-years from Earth and has a mass 6.5-billion times that of the Sun.

“This is a huge day in astrophysics,” said NSF Director France Córdova. “We’re seeing the unseeable. Black holes have sparked imaginations for decades. They have exotic properties and are mysterious to us. Yet with more observations like this one they are yielding their secrets. This is why NSF exists. We enable scientists and engineers to illuminate the unknown, to reveal the subtle and complex majesty of our universe.”

The EHT links telescopes around the globe to form an Earth-sized virtual telescope with unprecedented sensitivity and resolution. The EHT is the result of years of international collaboration and offers scientists a new way to study the most extreme objects in the Universe predicted by Einstein’s general relativity during the centennial year of the historic experiment that first confirmed the theory.

“We have taken the first picture of a black hole,” said EHT project director Sheperd S. Doeleman of the Center for Astrophysics | Harvard & Smithsonian. “This is an extraordinary scientific feat accomplished by a team of more than 200 researchers.”

The National Science Foundation (NSF) played a pivotal role in this discovery by funding individual investigators, interdisciplinary scientific teams and radio astronomy research facilities since the inception of EHT. Over the last two decades, NSF has directly funded more than $28 million in EHT research, the largest commitment of resources for the project.

Black holes are extraordinary cosmic objects with enormous masses but extremely compact sizes. The presence of these objects affects their environment in extreme ways, warping spacetime and super-heating any surrounding material.

“If immersed in a bright region, like a disc of glowing gas, we expect a black hole to create a dark region similar to a shadow — something predicted by Einstein’s general relativity that we’ve never seen before,” explained chair of the EHT Science Council Heino Falcke of Radboud University, the Netherlands. “This shadow, caused by the gravitational bending and capture of light by the event horizon, reveals a lot about the nature of these fascinating objects and allowed us to measure the enormous mass of M87’s black hole.”

Streaming out from the center of M87 like a cosmic searchlight is one of nature’s most amazing phenomena: a black-hole-powered jet of subatomic particles traveling at nearly the speed of light. In this Hubble image, the blue jet contrasts with the yellow glow from the combined light of billions of unresolved stars and the point-like clusters of stars that make up this galaxy. Credits: NASA and the Hubble Heritage Team (STScI/AURA)

Streaming out from the center of M87 like a cosmic searchlight is one of nature’s most amazing phenomena: a black-hole-powered jet of subatomic particles traveling at nearly the speed of light. In this Hubble image, the blue jet contrasts with the yellow glow from the combined light of billions of unresolved stars and the point-like clusters of stars that make up this galaxy. Credits: NASA and the Hubble Heritage Team (STScI/AURA)

Multiple calibration and imaging methods have revealed a ring-like structure with a dark central region — the black hole’s shadow — that persisted over multiple independent EHT observations.
“Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well,” remarks Paul T.P. Ho, EHT Board member and Director of the East Asian Observatory. “This makes us confident about the interpretation of our observations, including our estimation of the black hole’s mass.”

Creating the EHT was a formidable challenge that required upgrading and connecting a worldwide network of eight preexisting telescopes deployed at a variety of challenging high-altitude sites. These locations included volcanoes in Hawaii and Mexico, mountains in Arizona and the Spanish Sierra Nevada, the Chilean Atacama Desert, and Antarctica.

The EHT observations use a technique called very-long-baseline interferometry (VLBI). which synchronizes telescope facilities around the world and exploits the rotation of our planet to form one huge, Earth-size telescope observing at a wavelength of 1.3mm. VLBI allows the EHT to achieve an angular resolution of 20 micro-arcseconds — enough to read a newspaper in New York from a sidewalk café in Paris.

The telescopes contributing to this result were ALMA, APEX, the IRAM 30-meter telescope, the James Clerk Maxwell Telescope, the Large Millimeter Telescope Alfonso Serrano, the Submillimeter Array, the Submillimeter Telescope, and the South Pole Telescope. Petabytes of raw data from the telescopes were combined by highly specialized supercomputers hosted by the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory.

The construction of the EHT and the observations announced today represent the culmination of decades of observational, technical, and theoretical work. This example of global teamwork required close collaboration by researchers from around the world. Thirteen partner institutions worked together to create the EHT, using both pre-existing infrastructure and support from a variety of agencies. Key funding was provided by the US National Science Foundation, the EU’s European Research Council (ERC), and funding agencies in East Asia.

“We have achieved something presumed to be impossible just a generation ago,” concluded Doeleman. “Breakthroughs in technology, connections between the world’s best radio observatories, and innovative algorithms all came together to open an entirely new window on black holes and the event horizon.”

An end to “Oppy”

StephensAstro —  February 13, 2019 — Leave a comment

In this navigation camera raw image, NASA's Opportunity Rover looks back over its own tracks on Aug. 4, 2010. Image Credit: NASA/JPL-Caltech

In this navigation camera raw image, NASA’s Opportunity Rover looks back over its own tracks in Martian soil on Aug. 4, 2010. Image Credit: NASA/JPL-Caltech


 

February 12, 2019 — One of the most successful and enduring feats of interplanetary exploration, NASA’s Opportunity rover mission is at an end after almost 15 years exploring the surface of Mars and helping lay the groundwork for NASA’s return to the Red Planet.

The Opportunity rover stopped communicating with Earth when a severe Mars-wide dust storm blanketed its location in June 2018. After more than a thousand commands to restore contact, engineers in the Space Flight Operations Facility at NASA’s Jet Propulsion Laboratory (JPL) made their last attempt to revive Opportunity Tuesday, to no avail. The solar-powered rover’s final communication was received June 10.

Artist's concept of the Spirit & Opportunity Mars Rovers. Image Credit: NASA

Artist’s concept of the Spirit & Opportunity Mars Rovers. Image Credit: NASA

“It is because of trailblazing missions such as Opportunity that there will come a day when our brave astronauts walk on the surface of Mars,” said NASA Administrator Jim Bridenstine. “And when that day arrives, some portion of that first footprint will be owned by the men and women of Opportunity, and a little rover that defied the odds and did so much in the name of exploration.”

Designed to last just 90 Martian days and travel 1,100 yards (1,000 meters), Opportunity vastly surpassed all expectations in its endurance, scientific value and longevity. In addition to exceeding its life expectancy by 60 times, the rover traveled more than 28 miles (45 kilometers) by the time it reached its most appropriate final resting spot on Mars – “Perseverance Valley.”

“For more than a decade, Opportunity has been an icon in the field of planetary exploration, teaching us about Mars’ ancient past as a wet, potentially habitable planet, and revealing uncharted Martian landscapes,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate. “Whatever loss we feel now must be tempered with the knowledge that the legacy of Opportunity continues – both on the surface of Mars with the Curiosity rover and InSight lander – and in the clean rooms of JPL, where the upcoming Mars 2020 rover is taking shape.”

Click here for more on NASA’s Mars rovers!