Sky & Telescope - August 2024 - 10

CHANDRA IMAGE OF CRAB PULSAR: X-RAY: NASA / CXC / SAO; OPTICAL: NASA / STSCI;
INFRARED: NASA / JPL-CALTECH; LRO IMAGE OF LUNAR CRATER: NASA
NEWS NOTES
SPACE MISSIONS
Chandra Observatory Faces
Premature End
AFTER A QUARTER-CENTURY in
space, NASA's Chandra X-ray Observatory
might face an early end to its
mission, at least according to the
President's new budget request for
NASA. Astronomers are now lobbying
to restore funding to the mission.
NASA's budget for 2025 as well as
projections for future years call for a
steep reduction in Chandra's funding.
This change would slash support not
only for telescope operations but also
for research projects in X-ray astronomy,
especially in the U.S. - which in
turn affects both professional astronomers
and students who rely on that
funding to do their work.
Chandra received $68.3 million for
normal operations in 2023. (Chandra
operated under a continuing resolution
in 2024.) Under the new fiscal year (FY)
2025 budget request, funding for the
telescope would drop to $41.1 million,
starting this October. Projections for
following years call for $26.6 million
for FY2026, 27, and 28, before dropping
to just $5 million by FY2029.
Patrick Slane (Center for Astrophysics,
Harvard & Smithsonian), director
of the Chandra X-ray Center, notes
that the FY2025 budget request is not
enough for the telescope to continue
making observations. In a letter to the
Chandra community, he states, " The
funding levels provided in the new budThis
composite image of the Crab Nebula
combines X-rays from Chandra (blue and white)
with visible and infrared data from Hubble
(purple) and Spitzer (pink), respectively.
SOLAR SYSTEM
Earth's Mini-moon Linked to Lunar Farside Crater
RESEARCHERS MIGHT HAVE located
the birthplace of 469219 Kamo'oalewa,
a small asteroid that has been described
as Earth's " mini-moon. "
Kamo'oalewa is the closest and most
stable of the quasi-satellites that -
despite not being bound by our planet's
gravity - co-orbit the Sun with Earth
over long time periods. Kamo'oalewa
has an orbit that takes it out as far as
100 times the distance of the Moon. It
also rotates quickly, spinning around
every 28 minutes.
In previous work, Ben Sharkey
(University of Arizona) and others have
suggested that the body has a lunar
origin, because its reflectance - the light
reflected back from its surface - is more
akin to that of samples collected from
the Moon than it is to observations of
near-Earth asteroids.
10 AUGUST 2024 * SKY & TELESCOPE
Yifei Jiao (Tsinghua University,
China) and colleagues set out to determine
which lunar crater is most likely
responsible by simulating impacts of
various sizes. They find that the originating
crater must be larger than 10 to
20 km. The team was able to further
Giordano Bruno Crater
on the Moon's farside
get plan are consistent with levels for
. . . closeout activities, but lower than
can accommodate operation of the
Chandra science mission. "
NASA cites Chandra's downgraded
performance as a reason to draw the
mission to an end, noting that an
increase in instrument temperature creates
restrictions in scheduling observations.
The efficiency at which the main
detector picks up the lowest-energy
X-rays has also decreased over the years
due to the build-up of contamination.
However, Slane notes that workarounds
are in place, resulting in good
science from Chandra's instruments
with no decrease in observing efficiency
or quality of science.
Astronomers in the community have
reacted to the news by starting a grassroots
organization, called SaveChandra
(savechandra.org), both to promote
awareness of the role the mission serves
in X-ray astronomy, especially in the
U.S., as well as to present a path for
rescuing the observatory.
¢DAVID DICKINSON
Find more details at https://is.gd/
ChandraBudget
whittle down the candidates because
Kamo'oalewa is younger than most of
the craters on the Moon. One candidate
remains the best fit: a 22-kilometerwide
crater on the farside of the Moon
called Giordano Bruno, made in an
impact some 1 to 10 million years ago.
The results were published April 19th in
Nature Astronomy.
Sherry Fieber-Beyer (University of
North Dakota), who wasn't involved in
the study, notes that the previous work
from Sharkey's team " laid the groundwork "
for Jiao and his team " to map the
dynamics straight back to the Moon. "
That connection, she says, " is equivalent
to finding a needle in a haystack. "
In 2025 China will launch Tianwen
2 to escort Kamo'oalewa for a few
months before dropping a lander to
retrieve samples. The mission will offer
the opportunity to study Kamo'oalewa
in more detail and verify its origin.
¢KIT GILCHRIST
http://www.savechandra.org https://is.gd/ChandraBudget https://is.gd/ChandraBudget
Sky & Telescope - August 2024

Table of Contents for the Digital Edition of Sky & Telescope - August 2024
