Sky and Telescope - June 2017 - 10

NEWS NOTES
BLACK HOLES

Interior of Dragon 2

SpaceX's 2018 Moonshot
SPACEX CEO and founder Elon Musk
announced on February 27th the company's intention to slingshot two people
around the Moon in late 2018.
The as-yet-unnamed individuals
approached SpaceX about the possible
mission and have reportedly already
paid a "signiﬁcant deposit" toward the
ﬂight. While not divulging the exact
price tag, Musk said that the total
amount would cost more than a seat on
a Russian Soyuz bound for the International Space Station (ISS) - $58 million.
SpaceX plans to conduct health and
ﬁtness tests with the applicants and
release additional information on just
who's going later this year.

The ﬂight will be with the company's
upcoming Falcon Heavy rocket and
Dragon 2 capsule, the latter developed
mostly with funding from NASA's Commercial Crew Program. Both have yet to
leave the launch pad. However, SpaceX
is under contract with the space agency
to resupply the ISS with cargo and crew,
with the ﬁrst crewed Dragon 2 mission
expected in 2018. To date, the company
has launched nine automated cargo
resupply missions to the station (eight
of them successful). These missions
used the Falcon 9 rocket and an unoccupied Dragon capsule.
The announced plan calls for the
inaugural ﬂight of the Falcon Heavy
rocket this summer, followed by an
uncrewed ﬂight of Dragon 2 to the ISS
toward the end of 2017.
Meanwhile, NASA is exploring the
possibility of ﬂying a crew on the ﬁrst
Space Launch System (SLS) mission,
slated for launch at the end of 2019. It
will also circle the Moon and return.
And China is already ahead of the
game in terms of big rockets that can
reach beyond low-altitude Earth orbit,
launching its Long March 5 rocket from
Wenchang Space Center last year on
November 3rd.

14 kpc

p This radio map reveals three strands of cool
gas along the borders of X-ray cavities (dotted line contours) blown out by the galaxy's
central black hole.

Black Holes Spur Starbirth
ASTRONOMERS HAVE discovered long

Intermediate Black Hole?

Organics on Ceres

Reporting in the February 9th Nature, Bülent
Kızıltan (Harvard-Smithsonian Center for
Astrophysics) and colleagues think they've
found signs of an intermediate-mass black
hole (IMBH). IMBHs are the long-sought
"middle children" in the spectrum of black
holes, neither supermassive beasts nor
small, star-made holes. No one has yet
found a definitive IMBH. But thanks to a
mathematical tool called Kullback-Leibler
divergence, originally developed by mathematicians and cryptanalysts, Kızıltan's team
thinks an IMBH lurks inside the massive
globular cluster 47 Tucanae. The team
analyzed the movements of 25 pulsars in the
cluster and concluded that they're orbiting
an unseen mass some 2,200 times the mass
of the Sun. However, skepticism remains.
Read more at https://is.gd/imbh47tuc.

NASA's Dawn spacecraft has found a big
patch of organic compounds high in the
northern hemisphere of the dwarf planet
Ceres. Although organics are unsurprising,
the spectrum Dawn picked up is clearer than
hints of these materials previously seen on
other main-belt asteroids, Maria Cristina De
Sanctis (INAF IAPS, Italy) and others report in
the February 17th Science. The compounds
drape over the southwestern floor and rim of
the 50-km-wide crater Ernutet; there's also a
much smaller deposit in Inamahari, about 400
km away. The compounds aren't related to
the craters or delivered by impacts; they likely
come from Ceres itself. Along with water ice,
carbonates, and salts - not to mention possible ice volcanism - the organic material
makes this world a promising environment for
prebiotic chemistry.

ﬁlaments of cold gas - the main ingredient for making stars - cocooning
giant bubbles inﬂated by a black hole.
The ﬁlaments are part of the central
galaxy in the hefty Phoenix Cluster.
Reporting in the February 10th Astrophysical Journal, Helen Russell (University of Cambridge, UK) and colleagues
used ALMA to ﬁnd that the galaxy's
black hole is powering intense jets that
have inﬂated huge bubbles of hot gas
(visible in X-ray observations). Seemingly wrapped around these cavities
are three gigantic ﬁlaments of cold,
molecular hydrogen gas - the stuff that
stars are made of. Each ﬁlament is tens
of thousands of light-years long.
Astronomers have seen hints of
ﬁlament-wrapped cavities before, but
the gaseous strands have generally been
messier, says Megan Donahue (Michigan
State University). Her team has looked
at more than two dozen central galaxies as part of the Hubble CLASH project
and seen very similar ﬁlaments, some
even with stars forming inside. Those
that are forming stars rank among the
most proliﬁc starbirthing galaxies in the
universe's last 5 billion years.
"It's kind of ironic, because they're
'supposed' to be red and dead," Donahue
says. Clusters' central galaxies are awash
in hot gas, which doesn't form stars.
Read more at https://is.gd/bhthermostat.

■ SHANNON HALL

■ CAMILLE M. CARLISLE

■ DAVID DICKINSON

IN BRIEF

2 arcsec

J U N E 2 0 1 7 * SK Y & TELESCOPE

BL ACK HOLE: H. RUSSELL E T A L. / ASTR OPHYSICAL JOUR NAL 2017 (836:130), © A AS REPRODUCED WITH PER MISSION; DR AGON 2: SPACE X

SPACE & SOCIETY

https://www.is.gd/imbh47tuc https://www.is.gd/bhthermostat

Sky and Telescope - June 2017

Table of Contents for the Digital Edition of Sky and Telescope - June 2017