space news updatespaceodyssey.dmns.org/media/87963/snu_200616.pdf · 2020. 6. 16. · the night sky...
TRANSCRIPT
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Space News Update — June 16, 2020 —
Contents
In the News
Story 1:
NASA’s IBEX Charts 11 Years of Change at Boundary to Interstellar Space
Story 2:
Black Holes Grow by Gas, Not Mergers, Most of Their Lives
Story 3:
NASA Selects Astrobotic to Fly Water-Hunting Rover to the Moon
Departments
The Night Sky
ISS Sighting Opportunities
NASA-TV Highlights
Space Calendar
Food for Thought
Space Image of the Week
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1. NASA’s IBEX Charts 11 Years of Change at Boundary to Interstellar
Space
Far, far beyond the orbits of the planets lie the hazy contours of the magnetic bubble in space that we call home.
This is the heliosphere, the vast bubble that is generated by the Sun’s magnetic field and envelops all the planets.
The borders of this cosmic bubble are not fixed. In response to the Sun’s gasps and sighs, they shrink and stretch
over the years.
Now, for the first time, scientists have used an entire solar cycle of data from NASA’s IBEX spacecraft to study how
the heliosphere changes over time. Solar cycles last roughly 11 years, as the Sun swings from seasons of high to
low activity, and back to high again. With IBEX’s long record, scientists were eager to examine how the Sun’s mood
swings play out at the edge of the heliosphere. The results show the shifting outer heliosphere in great detail, deftly
sketch the heliosphere’s shape (a matter of debate in recent years), and hint at processes behind one of its most
puzzling features. These findings, along with a newly fine-tuned data set, are published in The Astrophysical Journal
Supplements on June 10, 2020.
IBEX, short for the Interstellar Boundary Explorer, has been observing the boundary to interstellar space for more
than 11 years, showing us where our cosmic neighborhood fits in with the rest of the galaxy. “It’s this very small
mission,” said David McComas, the principal investigator for the mission at Princeton University in New Jersey. IBEX
is just as big as a bus tire. “It’s been hugely successful, lasting much longer than anybody anticipated. We’re lucky
now to have a whole solar cycle of observations.”
For the first time, scientists have used an entire solar cycle of data from NASA’s IBEX spacecraft to study how the
heliosphere—the vast magnetic bubble of space that we live in—changes over time.
Mapping the solar system’s edge, one particle at a time
The heliosphere is filled with the solar wind, the constant flow of charged particles from the Sun. The solar wind
rushes out in all directions, a million miles per hour, until it butts against the interstellar medium, winds from other
stars that fill the space between them.
As the Sun wades through the interstellar medium, it generates a hot, dense wave much like the wave at the front
of a boat coursing through the sea. Our cosmic neighborhood is called the Local Fluff, for the cloud of superhot
gases that blooms around us. Where the solar wind and Local Fluff meet forms the edge of the heliosphere, called
the heliopause. Just inside that lies a turbulent region called the heliosheath.
Particles called energetic neutral atoms, or ENAs, that are formed in this distant region of space are the focus of
IBEX’s surveys. They’re created when hot, charged particles like the ones in the solar wind collide with cold neutrals
like those flowing in from interstellar space. Zippy solar wind particles can snatch electrons from lumbering
interstellar atoms, becoming neutral themselves.
As the Sun wades through the interstellar medium, it generates a
hot, dense wave like the wave at the front of a boat coursing through the sea. In this illustration, this is the boundary in darker blue. IBEX has
helped scientists determine the shape of the heliosphere, which has a comet-like tail. Credits: NASA’s
Scientific Visualization Studio/Conceptual Imaging Lab
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The journey of these particles begins long before IBEX detects them. Past the planets, past the asteroid belt and
the Kuiper Belt, to the edge of the heliosphere, it takes about a year for a gust of solar wind to race 100 times the
distance between the Sun and Earth. Along the way, the solar wind picks up ionized atoms of interstellar gases that
have wriggled in to the heliosphere. The solar wind that arrives at the edge is not the same wind that left the Sun a
year before.
Solar wind particles might spend another six months roving the chaos of the heliosheath, the gulf between the
heliosphere’s two outer boundaries. Inevitably, some collide with interstellar gases and become energetic neutrals.
It takes the neutral particles close to another year for the return trip, traversing the space from the edge of the
heliosphere to reach IBEX — if the particles happened to be heading in precisely the right direction. Of all the
neutral particles formed, only a few actually make it to IBEX. The whole trip takes two to three years for the
highest-energy particles in IBEX’s observing range, and even longer at lower energies or more distant regions.
IBEX takes advantage of the fact that neutral atoms like these aren’t diverted by the Sun’s magnetic field: Fresh
neutral particles bound away from collisions in nearly a straight line. IBEX surveys the skies for the particles, noting
their direction and energy. The spacecraft only detects about one every other second. The result is a map of the
interstellar boundary, crafted from the same principle a bat uses to echolocate its way through the night: monitor
an incoming signal to learn more about one’s surroundings. By studying where the neutrals come from, and when,
IBEX can trace the remote boundaries of our heliosphere.
“We’re so lucky to observe this from inside the heliosphere,” said Justyna Sokol, a visiting scientist on the Princeton
team. “These are processes that happen at very small distances. When you observe other stars that are very far
away, you observe distances of light years, from outside their astrospheres.” Even the distance between the Sun
and the nose of the heliosphere is tiny compared to many, many light years.
Using IBEX’s 11-plus years of data, McComas and his team were able to study changes that evolve over time and
are key to understanding our place in space.
The solar wind is constant, but the wind is not steady. When the wind gusts, the heliosphere inflates like a balloon,
and neutral particles surge at the outer fringes. When the wind calms, the balloon contracts; neutral particles
dwindle. The ensuing seesaw of neutral particles, the scientists reported, consistently echoed two to three years
after the changes in the wind — reflecting their journey to the edge of this balloon and back.
“It takes so many years for these effects to reach the edge of the heliosphere,” said Jamey Szalay, another
Princeton researcher on the team. “For us to have this much data from IBEX, finally allows us to make these long-
term correlations."
Shaping up the heliosphere
From 2009 to 2014, the wind blew fairly low and steady, a gentle breeze. The heliosphere contracted. Then came a
surprise swell in the solar wind, as if the Sun heaved a great sigh. In late 2014, NASA spacecraft orbiting Earth
detected the solar wind pressure increase by about 50% (it has since remained high for several years).
Two years later, the billowing solar wind led to a flurry of neutral particles in the heliosheath. Another two years
later, they filled most of the nose of the heliosphere. Eventually, they crested over the heliosphere’s north and
south poles. These changes were not symmetric. Each observed bump traced the quirks of the heliosphere’s shape.
The scientists were surprised at how clearly they saw the tidal wave of solar wind pushing out the heliopause.
“Time and the neutral particles have really painted the distances in the shape of the heliosphere for us,” McComas
said.
IBEX still hasn’t observed the effects of this cosmic punch from the back end of the heliosphere, the heliotail. That
means the tail end is much farther away from the Sun than the front; those particles are on a much longer journey.
Maybe the solar wind surge is still hurtling toward the tail, or maybe neutral particles are already on their way back.
In the coming years, the IBEX team will be watching for signs of their return from the tail. “Nature set up this
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perfect experiment for us to better understand this boundary,” Szalay said. “We got to see what happens when this
one big thing — the solar wind push — changes.”
Overall, this paints a picture of the heliosphere that is shaped something like a comet. The shape of the heliosphere
has been a matter of debate in recent years. Some have argued our bubble in space is spherical as a globe; others
suggested it is closer to a croissant. But in this study, McComas said, IBEX data clearly shows the heliosphere’s
response to the solar wind push was asymmetric — so the heliosphere itself must be asymmetric too. The Sun is
situated close to the front, and as the Sun hurtles through space, the heliotail trails much farther behind, something
like the streaking tail of a comet.
Tackling IBEX’s biggest puzzle
IBEX’s many years of data have also brought scientists closer to an explanation for one of the heliosphere’s more
puzzling features, known as the IBEX ribbon. The ribbon remains one of IBEX’s biggest discoveries. Announced in
2009, it refers to a vast, diagonal swath of energetic neutrals, painted across the front of the heliosphere. It’s long
puzzled scientists: Why should any part of the boundary should be so different from the rest?
Over time, IBEX has indicated that what forms the ribbon is very different than what forms the rest of the
interstellar sky. It is shaped by the direction of the interstellar magnetic field. But how are ribbon particles
produced? Now, the scientists report that it’s very likely a secondary process is responsible, causing the journey of a
certain group of energetic neutral particles to roughly double.
After becoming energetic neutrals, rather than ricochet back toward IBEX, this group of particles would streak in the
opposite direction, across the heliopause and into interstellar space. There, they’d get a taste of the Local Fluff,
cruising until some would inevitably collide with passing charged particles, losing an electron once again and
becoming tied to the surrounding magnetic field.
Another two years or so pass, and the charged particles might collide yet again with slower peers, stealing electrons
like they’ve done before. After this brief migration beyond the heliosphere, the twice-born energetic neutrals might
eventually re-enter, hurtling back toward home.
Extended IBEX data helped the scientists connect the ribbon to the particles’ long interstellar tour. Particles forming
the ribbon have journeyed some two years more than the rest of the neutral particles observed. When it came to
the solar wind spike, the ribbon took another two years after the rest of the heliosphere to even start responding.
Far exceeding its initial mission of two years, IBEX will soon be joined by another NASA mission, IMAP — short for
the Interstellar Mapping and Acceleration Probe, for which McComas also serves as principal investigator. The
mission is scheduled to launch in late 2024.
Source: NASA Return to Contents
The ribbon remains one of IBEX’s
biggest discoveries. It refers to a vast, diagonal swath of energetic neutrals, painted across the
front of the heliosphere.
Credits: NASA/IBEX
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2. Black Holes Grow by Gas, Not Mergers, Most of Their Lives
Black holes predominantly grow in different ways in the early (distant) universe than in recent (nearby) cosmic times. In
the last few billion years, smaller black holes have grown by accretion while larger black holes grow by mergers. But less
than a billion years after the Big Bang phase, the opposite was true.
M. Weiss
Calculations suggest how black holes have amassed mass and predict what the black holes’ spins should be if this
picture is correct. Most of the growth black holes experience is due to guzzling gas and not by merging with other
black holes, Fabio Pacucci (Harvard’s Black Hole Initiative) reported June 1st at the virtual American Astronomical
Society summer meeting.
Black holes come in a panoply of sizes, with masses ranging from a few Suns to billions of them. The largest ones
are tied to their host galaxies’ growth in a symbiosis that astronomers don’t yet understand. Nor do we know how
the biggest behemoths came to be as massive as they are as early as they did.
To explore how black holes grow at different times in cosmic history, Pacucci and Abraham Loeb (also Harvard BHI)
followed the objects’ evolution computationally. They started with a range of “seed” black holes, tens of solar
masses and larger. Based on both observations and theoretical work, the astronomers made various assumptions
about how fast the black holes would scarf down gas and how often they’d collide with their brethren. Then they
followed the black holes over billions of simulated years.
The calculations, which also appear in the June 1st Astrophysical Journal, indicate that for black holes with masses
between thousands and billions of Suns, accretion is the primary way the objects grow across all cosmic epochs.
That’s especially true for the gargantuas in the universe’s first billion years or so, as well as black holes of
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thousands of solar masses today. (Astronomers are still working to find black holes of this smaller size.) This chart
adapted from the team’s paper sums everything up:
Previous calculations have suggested that black holes grown by gas accretion spin much faster — often at least
90% of their maximum — than those that beef up via mergers. Pacucci and Loeb thus predict that in today’s
universe, smaller black holes should spin quickly, but leviathans of hundreds of millions of solar masses or greater
will spin slower, more like half their maximum rate. When they tested this prediction by sorting 23 real spin
measurements for black holes with a range of masses, they saw hints that their prediction is correct.
Black hole astrophysicist Laura Brenneman (Center for Astrophysics, Harvard & Smithsonian) says the team’s study
is well thought out and compelling. But she cautions against concluding too quickly that the real universe matches
the predictions. “Measuring black hole spin requires a lot of photons collected from very close to the event horizon,”
she explains. With current instruments, that can require a day’s worth of exposure time to measure the rotation of a
single bright, nearby object. “That’s a big reason why there are so few measured supermassive black hole spins in
the literature right now: These are ‘expensive’ observations.”
What few spins astronomers do have come with notable uncertainties, and they’re likely biased toward high spins,
work by Brenneman and others suggests. Ideally, astronomers would have hundreds of spin measurements before
drawing conclusions about black holes’ pasts.
Pacucci acknowledges that the spin measurements aren’t precise, and he and Brenneman both also note that
chaotic accretion — which the team didn’t take into account and might be particularly important early on — could
change the effect on spin. But he’s encouraged by the fact that, when he and Loeb removed the less certain
measurements and focused on the subset of better ones, they see the same trend.
How black holes grow also affects how we detect them. If black holes merge, then we’ll catch them with
gravitational waves. If they surround themselves with blazing hot smorgasbords of gas, then we’ll find them with X-
rays.
“It will be very interesting to see whether Pacucci and Loeb’s conclusions and predictions hold up in the 2030s as
we launch the next generation of revolutionary X-ray and gravitational-wave observatories,” Brenneman concludes.
Reference: F. Pacucci and A. Loeb. “Separating Accretion and Mergers in the Cosmic Growth of Black Holes with X-
ray and Gravitational Wave Observations.” Astrophysical Journal. June 1, 2020. Full text on the arXiv.
Source: Sky and Telescope Return to Contents
The ratio of black holes’ growth rates by gas accretion and merger.
Mass is on the x-axis and is logarithmic (e.g., 3 means 103, or 1,000 solar masses). Bluer colors
indicate accretion dominates. Mergers win out only for runt
massive black holes (smaller than 100,000 solar masses) in the early
universe and the largest supermassive black holes today. The dash-dotted line is where accretion and mergers play an
equal role. Adapted from F. Pacucci & A. Loeb
/ Astrophysical Journal2020
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3. NASA Selects Astrobotic to Fly Water-Hunting Rover to the Moon
Illustration of NASA's Volatiles Investigating Polar Exploration Rover (VIPER) on the surface of the Moon Credits: NASA Ames/Daniel Rutter
NASA has awarded Astrobotic of Pittsburgh $199.5 million to deliver NASA’s Volatiles Investigating Polar
Exploration Rover (VIPER) to the Moon’s South Pole in late 2023.
The water-seeking mobile VIPER robot will help pave the way for astronaut missions to the lunar surface
beginning in 2024 and will bring NASA a step closer to developing a sustainable, long-term presence on the
Moon as part of the agency’s Artemis program.
“The VIPER rover and the commercial partnership that will deliver it to the Moon are a prime example of how
the scientific community and U.S. industry are making NASA’s lunar exploration vision a reality,” said NASA
Administrator Jim Bridenstine. “Commercial partners are changing the landscape of space exploration, and
VIPER is going to be a big boost to our efforts to send the first woman and next man to the lunar surface in
2024 through the Artemis program.”
VIPER’s flight to the Moon is part of NASA’s Commercial Lunar Payload Services (CLPS) initiative, which
leverages the capabilities of industry partners to quickly deliver scientific instruments and technology
demonstrations to the Moon. As part of its award, Astrobotic is responsible for end-to-end services for delivery
of VIPER, including integration with its Griffin lander, launch from Earth, and landing on the Moon.
During its 100-Earth-day mission, the approximately 1,000-pound VIPER rover will roam several miles and use
its four science instruments to sample various soil environments. Versions of its three water-hunting
instruments are flying to the Moon on earlier CLPS lander deliveries in 2021 and 2022 to help test their
performance on the lunar surface prior to VIPER’s mission. The rover also will have a drill to bore
approximately 3 feet into the lunar surface.
“CLPS is a totally creative way to advance lunar exploration,” said NASA’s Associate Administrator for Science
Thomas Zurbuchen. “We’re doing something that’s never been done before – testing the instruments on the
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Moon as the rover is being developed. VIPER and the many payloads we will send to the lunar surface in the
next few years are going to help us realize the Moon’s vast scientific potential.”
NASA’s water-seeking robotic Moon rover just booked a ride to the Moon’s South Pole. Astrobotic of Pittsburgh
has been selected to deliver the Volatiles Investigating Polar Exploration Rover, or VIPER, to the Moon in 2023.
During its 100-Earth-day mission, the approximately 1,000-pound rover will roam several miles and use its four
science instruments to sample various soil environments in search of water ice. Its survey will help pave the
way for a new era of human missions to the lunar surface and will bring us a step closer to developing a
sustainable, long-term robotic and human presence on the Moon as part of the Artemis program.
VIPER will collect data – including the location and concentration of ice – that will be used to inform the first
global water resource maps of the Moon. Scientific data gathered by VIPER also will inform the selection of
future landing sites for astronaut Artemis missions by helping to determine locations where water and other
resources can be harvested to sustain humans during extended expeditions. Its science investigations will
provide insights into the evolution of the Moon and the Earth-Moon system.
NASA has previously contracted with three companies to make CLPS deliveries to the Moon beginning in 2021.
Astrobotic is scheduled to make its first delivery of other instruments to the lunar surface next year. In April,
the agency released a call for potential future lunar surface investigations and received more than 200
responses. CLPS is planned to provide a steady cadence of two delivery opportunities to the lunar surface each
year.
Source: NASA
*********
Yes, There's Ice on the Moon. But It's Not the 1st Lunar Resource We'll need to Use
Listen to a couple ideas about humanity's future on the moon and you'll likely hear about the game-changing
potential of a substance you probably have in your freezer: water ice.
An image of the moon's south pole shows illumination over
time, with the depths of Shackleton Crater near the center of the frame. Image Credit: NASA/GSFC/Arizona
State University
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Would-be explorers have high hopes they can harvest ice hidden below the moon's surface, both for
astronauts to drink and to make rocket fuels to make round trips cheaper. But the image of robots tearing up
the lunar surface and processing frozen water out from other compounds skips a step in considering resources
on the moon. Ice will never be the first resource humans use on the moon, experts emphasized at a recent
scientific conference.
Instead, it will be sunlight.
"The first and easiest resource that we have there is solar energy," Jake Bleacher, a geologist and chief
exploration scientist at NASA headquarters in Washington, said during the Lunar Surface Science Virtual
Workshop held digitally on May 28.
Energy means power, particularly for operating instruments on the lunar surface, as well as for supporting the
long-term base on the moon that NASA plans to build as part of the agency's Artemis program, the short-term
goal of which is to land humans at the south pole by 2024.
The two resources are direct opposites and both rely on how the moon aligns with the sun. Unlike Earth's, the
axis on which the moon rotates is more or less perpendicular to the plane of the solar system, which contains
the sun, Earth and moon. It's Earth's axial tilt that gives us seasons, as one hemisphere tilts to receive more
sunlight, making incredibly long days at the pole, then much less for a near-constant polar night.
Not so on the moon. There, the daily cycle is constant. At the poles, the lack of tilt means light and dark are
governed in large part by terrain, as more elevated locations block sunlight from reaching lower areas.
On the dark side of this divide are permanently shadowed regions, many in the craters that scar the moon's
surface, where temperatures are always cold enough that water ice remains frozen. On the light side of the
divide are locations sometimes nicknamed the "peaks of eternal light" — and it's here that the first lunar
resource harvesters would go, exploration experts say.
"The polar location, which was specified by the [Artemis program mandate from the National] Space Council,
is enabling because of the existence of the locations of near-permanent sunlight," Sam Lawrence, a planetary
scientist at NASA's Johnson Space Center in Houston, said during his own presentation on the same day. "It is
the illumination that's a resource."
Nevertheless, it's the potential for water ice that prompts the most discussion during these meetings and stars
in NASA's written visions for how lunar exploration will become sustainable under the Artemis program.
"We heard a lot about the polar volatiles story and, to be sure, it's a good one," Lawrence said. "But it's the
illumination that is the resource we're actually going after with the Artemis missions."
Source: Space.com Return to Contents
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The Night Sky
FRIDAY, JUNE 5
THURSDAY, JUNE 18
In Friday's dawn, bring binoculars to a location with a view very low to the east-northeast to catch the thin
crescent Moon paired with Venus, as illustrated above. For North America they'll appear only a degree or two
apart. This will be a challenging photo opportunity; bring your best camera, a tripod, and a long lens.
FRIDAY, JUNE 19
Leo the Lion is mostly a constellation of late winter and spring. But he's not gone yet. As twilight ends look due
west, somewhat low, for Regulus, his brightest and now lowest star: the forefoot of the Lion stick figure.
The Sickle of Leo extends upper right from Regulus. The rest of the Lion's constellation figure extends for
almost three fists to the upper left, to his tail star Denebola, the highest. He'll soon be treading away into the
sunset.
SATURDAY, JUNE 20
The June solstice arrives today at 5:44 p.m. EDT (21:44 UT). This is when the Sun reaches its northernmost
declination in Earth's sky and begins its six-month return southward. Summer begins in the Northern
Hemisphere, winter in the Southern Hemisphere. For us northerners, this is the longest day and shortest night
of the year.
It's also the day when (in the north temperate latitudes) the midday Sun passes the closest it ever can to being
straight overhead, and thus when your shadow becomes the shortest it can ever be at your location.
Source: Sky and Telescope Return to Contents
TUESDAY, JUNE 16
After dark, Vega dominates the eastern sky. Barely lower
left of it is 4th-magnitude Epsilon Lyrae, the famous
Double-Double. Epsilon forms one corner of a roughly
equilateral triangle with Vega and Zeta Lyrae. The triangle
is less than 2° on a side, hardly the width of your thumb at
arm's length.
Binoculars easily resolve Epsilon. And a 4-inch telescope at
100× or more should resolve each of Epsilon's wide
components into a tight pair.
Zeta Lyrae is also a double star for binoculars; much closer
and tougher, but plainly resolved in any telescope. And
Delta Lyrae, below Zeta, is a much wider and easier pair.
WEDNESDAY, JUNE 17
Arcturus, magnitude zero – as bright as Vega – shines pale
yellow-orange high overhead toward the south. Bootes the
cowherd, its constellation, extends in a kite shape up from
Arcturus. The kite is narrow, slightly bent, and 23° long:
about two fists at arm's length.
Just east (left) of the Bootes kite is the pretty but dim
semicircle of Corona Borealis, the Northern Crown. It has
only one modestly bright star, 2nd-magnitude Alphecca or
Gemma: its crown jewel.
The waning Moon, after passing Mars on the mornings of June 12th and 13th, heads toward
Venus shining very low in bright dawn. The Moon and Venus hang together on the morning of the
19th. Note that the Moon is drawn here three times larger than its actual apparent size. And the visibility
of faint objects in bright twilight is exaggerated here, so bring binoculars.
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ISS Sighting Opportunities (from Denver)
There are no sightings in Denver for the period of Monday Jun 8, 2020 through Wednesday Jun 24, 2020
Sighting information for other cities can be found at NASA’s Satellite Sighting Information
NASA-TV Highlights (all times Eastern Time Zone)
Regularly Scheduled Programming
NASA TV Schedule for Week of June 15
Live Programming
June 16, Tuesday
11:30 a.m. – International Space Station Expedition 63 in-flight interviews with CBS News, CNN and Fox
Business News and NASA astronauts Bob Behnken and Doug Hurley (All Channels)
June 17, Wednesday
2 p.m. – Media briefing on upcoming launch of the Mars Perseverance Rover from the Jet Propulsion Lab
(All Channels)
June 19, Friday
11 a.m. - SpaceCast Weekly (All Channels)
1:10 p.m. – International Space Station Expedition 63 in-flight educational event with recorded questions
from students at Challenger Learning Centers and Expedition 63 Commander Chris Cassidy and NASA
astronauts Bob Behnken and Doug Hurley (All Channels)
Watch NASA TV online by going to the NASA website. Return to Contents
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Space Calendar
Jun 16 - Beidou 3 CZ-3B Launch
Jun 16 - Apollo Asteroid 2020 KP6 Near-Earth Flyby (0.009 AU)
Jun 16 - Aten Asteroid 2014 OL339 Closest Approach To Earth (0.299 AU)
Jun 16 - eRum2020 Satellite Online Event: Hackathon on Spatial Networks
Jun 16 - Online: Teaching Space with NASA - Introducing the Perseverance Mars Rover
Jun 16-17 - Online: Space Weather Operations and Research Infrastructure Workshop Part 1
Jun 17 - Gaofen 9-03 CZ-2D Launch
Jun 17 - Apollo Asteroid 2020 JU3 Near-Earth Flyby (0.018 AU)
Jun 17 - Asteroid 5945 Roachapproach Closest Approach To Earth (1.018 AU)
Jun 17 - Mapping Science Committee Virtual Meeting: Geospatial Needs for a Pandemic-Resilient World
Jun 17 - Online Lecture: The Far Side of the Moon
Jun 17 - Online Lecture: Early Asteroid Impact Detection - Defending the Planet One Asteroid at a Time
Jun 17 - Online Colloquium: Pulsar Observation and Study with FAST and the Parkes Radio Telescope
Jun 17 - FOSS4GUK 2020 Online Event
Jun 18 - SSMS (POC)/ ESAIL/ Athena/ ION CubeSat Carrier/ NEMO-HD/ GHGSat C1/ Astrocast 1.1-1.10/ PICASSO/ SIMBA/ DIDO 3/ QARMAN/ TRISAT Vega Launch
Jun 18 - Comet C/2019 U6 (Lemmon) Perihelion (0.914 AU)
Jun 18 - Apollo Asteroid 2020 LG Near-Earth Flyby (0.023 AU)
Jun 18 - Apollo Asteroid 2020 KF3 Near-Earth Flyby (0.033 AU)
Jun 18 - Online Lecture: Making a Mars Rover,
Jun 18 - Webinar: The How, When, and Why of Using EO data in Climate Resilience Decision-making
Jun 18-19 - International Conference on Advances in Astronomical Computing (ICAAC 2020), Vienna, Austria
Jun 18-19 - International Conference on Astrophysics and Cosmology (ICAC 2020), Vienna, Austria
Jun 18-19 - International Conference on Astrophysics and Astroparticles (ICAA 2020), Riga, Latvia
Jun 18-19 - NASA's Exoplanet Exploration Program Analysis Group (ExoPAG) Virtual Meeting
Jun 19 - Moon Occults Venus
Jun 19 - Asteroid 344 Desiderata Occults UCAC4 578-47209 (6.5 Magnitude Star)
Jun 19 - Aten Asteroid 2018 PD22 Near-Earth Flyby (0.044 AU)
Jun 19 - Apollo Asteroid 2101 Adonis Closest Approach To Earth (0.368 AU)
Jun 19 - Apollo Asteroid 2102 Tantalus Closest Approach To Earth (0.483 AU)
Jun 20 - Summer Solstice, 21:44 UT
Jun 20 - Online Lecture: The BIS Von Karman Line Buster
Jun 20-22 - Workshop: Matrix Membranes and Emergent Spacetime, Dublin, Ireland
Source: JPL Space Calendar Return to Contents
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Food for Thought
Research Sheds New Light on Intelligent Life Existing Across the
Galaxy
Credit: CC0 Public Domain
Is there anyone out there? This is an age-old question that researchers have now shed new light on with a
study that calculates there could be more than 30 intelligent civilizations throughout our Galaxy. This is an
enormous advance over previous estimates which spanned from zero to billions.
One of the biggest and longest-standing questions in the history of human thought is whether there are other
intelligent life forms within our Universe. Obtaining good estimates of the number of possible extraterrestrial
civilizations has however been very challenging.
A new study led by the University of Nottingham and published today in The Astrophysical Journal has taken a
new approach to this problem. Using the assumption that intelligent life forms on other planets in a similar
way as it does on Earth, researchers have obtained an estimate for the number of intelligent communicating
civilizations within our own galaxy -the Milky Way. They calculate that there could be over 30 active
communicating intelligent civilizations in our home Galaxy.
Professor of Astrophysics at the University of Nottingham, Christopher Conselice who led the research,
explains: "There should be at least a few dozen active civilizations in our Galaxy under the assumption that it
takes 5 billion years for intelligent life to form on other planets, as on Earth." Conselice also explains that, "The
idea is looking at evolution, but on a cosmic scale. We call this calculation the Astrobiological Copernican
Limit."
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First author Tom Westby explains: "The classic method for estimating the number of intelligent civilizations
relies on making guesses of values relating to life, whereby opinions about such matters vary quite
substantially. Our new study simplifies these assumptions using new data, giving us a solid estimate of the
number of civilizations in our Galaxy.
The two Astrobiological Copernican limits are that intelligent life forms in less than 5 billion years, or after
about 5 billion years—similar to on Earth where a communicating civilization formed after 4.5 billion years. In
the strong criteria, whereby a metal content equal to that of the Sun is needed (the Sun is relatively speaking
quite metal rich), we calculate that there should be around 36 active civilizations in our Galaxy."
The research shows that the number of civilizations depends strongly on how long they are actively sending
out signals of their existence into space, such as radio transmissions from satellites, television, etc. If other
technological civilizations last as long as ours which is currently 100 years old, then there will be about 36
ongoing intelligent technical civilizations throughout our Galaxy.
However, the average distance to these civilizations would be 17,000 light-years away, making detection and
communication very difficult with our present technology. It is also possible that we are the only civilization
within our Galaxy unless the survival times of civilizations like our own are long.
Professor Conselice continues: "Our new research suggests that searches for extraterrestrial intelligent
civilizations not only reveals the existence of how life forms, but also gives us clues for how long our own
civilization will last. If we find that intelligent life is common then this would reveal that our civilization could
exist for much longer than a few hundred years, alternatively if we find that there are no active civilizations in
our Galaxy it is a bad sign for our own long-term existence. By searching for extraterrestrial intelligent life—
even if we find nothing—we are discovering our own future and fate."
Source: Phys.org/University of Nottingham Return to Contents
The world’s largest polar-aligned telescope is this radio telescope in
Green Bank, West Virginia. The telescope’s axis is aimed at Polaris
(The North Pole, or area below the North Star) so that it can follow the sky
as the Earth spins. In this photograph, we are able to view the 140-
foot (43-meter) telescope from the
south and lit against the dust-shrouded heart of our Milky Way galaxy. Credit: NRAO/AUI/NSF
15 of 15
Space Image of the Week
Barred Spiral Galaxy NGC 1300 Image Credit: Hubble Heritage Team, ESA, NASA
Explanation: Big, beautiful, barred spiral galaxy NGC 1300 lies some 70 million light-years away on the banks of the constellation Eridanus. This Hubble Space Telescope composite view of the gorgeous island universe is one of the largest Hubble images ever made of a complete galaxy. NGC 1300 spans over 100,000 light-years and the Hubble image reveals striking details of the galaxy's dominant central bar and majestic spiral arms. In fact, on close inspection the nucleus of this classic barred spiral itself shows a remarkable region of spiral structure about 3,000 light-years across. Like other spiral galaxies, including our own Milky Way, NGC 1300 is thought to have a supermassive central black hole.
Source: NASA APOD Return to Contents