Sky & Telescope - USA (2020-06)

(Antfer) #1

NEWS NOTES


12 JUNE 2020 • SKY & TELESCOPE


IN BRIEF


Amateur Dennis Conti Wins
Chambliss Award
The American Astronomical Society has con-
ferred the Chambliss Amateur Achievement
Award on Dennis Conti for “his outstanding
observational, computational, and educa-
tional contributions to exoplanet studies.”
Conti, a computer scientist and amateur
astronomer, has been heavily involved with
the exoplanet community since 2016, when
he helped coordinate a worldwide network of
amateur astronomers. Together, they provided
observations complementing a Hubble Space
Telescope program searching for water
in exoplanet atmospheres. More recently,
Conti took the helm of a group of amateurs
at the American Association of Variable Star
Observers working with NASA’s Transiting
Exoplanet Survey Satellite (TESS). In this role,
Conti contributes observations and trains and
mentors other observers. He also contributed
a key piece of TESS’s object identifi cation
algorithm, which helps identify signals that are
not really planets. Conti says the most thrilling
discovery he has contributed to so far is the
discovery and validation of the TOI-700 triple-
planet system. This triplet includes the fi rst
habitable-zone Earth-size planet that TESS
has identifi ed.
■DIANA HANNIKAINEN

SOLAR SYSTEM
Earth’s New (and
Temporar y) Mini-Moon
EARTH RECENTLY TOOK ON a brand
new moon. Designated 2020 CD 3 ,
it was discovered on February 15th
by Catalina Sky Survey astronomers
Kacper Wierzchos and Teddy Pruyne.
At the time, the object was a 20th-
magnitude pinpoint about 300,000 km
(186,000 miles) from Earth. Combin-
ing brightness and distance infor-
mation, astronomers estimated the
asteroid’s diameter at 6 to 12 feet (2 to
3.5 meters) — about as wide across as an
elephant is tall.
Additional measurements soon
revealed that the space rock wasn’t
orbiting the Sun, but rather was going
around Earth — though only tempo-
rarily. Working the orbit backwards,

astronomers concluded that Earth’s
gravity had snared the mini-moon
several years ago. The asteroid went
undetected for so long because it’s tiny
— and therefore faint — and because it
orbits our planet in meandering loops of
varying eccentricity and inclination.
Our sojourn with 2020 CD 3 will be
brief: Astronomers expected the boulder
to return to a solar orbit by April.

As with any Earth-approaching aster-
oid, there’s always a small probability
that it can come back to bite us — but
that won’t happen this time around.
And while preliminary analysis from
the JPL’s Sentry project indicated a 3%
probability of impact within the next
century, we wouldn’t have to worry even
if it did collide with Earth. Objects this
size typically fragment when they strike
the atmosphere, so at worst it would
land as numerous small meteorites.
Earth has had one other known
mini-moon, 2006 RH 120 , discovered by
Catalina Sky Survey astronomer Eric
Christensen. It dawdled in our neigh-
borhood for about a year before getting
the boot. The objects likely represent
only a small fraction of the mini-moons
Earth has captured and released since
its youth.
■BOB KING

pThe new mini-moon, designated 2020 CD 3

Betelgeuse Rises Again
After declining in brightness to a record-
breaking minimum (S&T: Apr. 2020, p. 10),
Betelgeuse, the bright red giant sitting at
Orion’s left shoulder, fi nally began brighten-
ing again in late February. Edward Guinan
(Villanova University) and colleagues report in
Astronomer’s Telegram #13512 that the star
bottomed out at magnitude 1.61 in mid-Feb-
ruary. This low point occurred 420–428 days
after the star’s last minimum in mid-December
2018, when it had dimmed to magnitude 0.
— part of a long cycle in brightness variations
caused by turbulence below the star’s surface
layers. However, it remains unclear why the
star dimmed so much this time around. In
a related Astronomer’s Telegram #13518,
Robert Gehrz (University of Minnesota) and
colleagues reported that at infrared wave-
lengths, Betelgeuse has remained “steadfast”
over the past 50 years. The team suggests
that the recent fading at visual wavelengths
is therefore more likely due to “local surface
phenomena,” such as changes in the amount
of foreground dust and gas belched out by
the star along Earth’s line of sight, or varia-
tions in surface temperature. The star may
yet explode tomorrow or in the next 100,
years, Gehrz and colleagues write, but the
recent “fainting” episode is not a harbinger of
the star’s core collapse.
■BOB KING

NASA 2021 Budget
Proposal
The current administration has released
its request for NASA’s budget for the fi scal
year of 2021, a proposal that emphasizes
human exploration at the cost of several key
programs. The space agency would receive
$25.2 billion overall, but while this represents
a 12% increase over the received budget in
2020, the majority of this increase would go
toward the Artemis initiative, which aims to
put people back on the Moon by 2024. Proj-
ects to build the Lunar Gateway, which would
orbit the Moon, and a lunar lander, which
would take astronauts to the surface, both
received increases under the current pro-
posal. In return, several science missions are
zeroed out, including the Wide-Field Infrared
Survey Telescope (WFIRST), the Stratospheric
Observatory for Infrared Astronomy (SOFIA),
NASA’s Offi ce of STEM Engagement, and two
Earth science missions. The proposal would
also suspend NASA’s Near-Earth Object
Surveillance Mission, a space-based infrared
telescope that would hunt for potentially
hazardous asteroids. Many of these missions
have faced termination several times before,
though, and managed to survive thanks to
Congressional intervention.
■DAVID DICKINSON
Read more budget details at https://
is.gd/NASAbudget2021. GEMINI OBSERVATORY
Free download pdf