Sky and Telescope - January 2018 - 12

NEWS NOTES
LUNAR

Ancient Moon Had Volcano-generated Atmosphere

Artist's concept of the ancient Moon's
volcano-produced atmosphere

Intense eruptions that created the
Moon's dark volcanic plains, or maria,
might have released enough gas to
create a thin atmosphere, a new study
published in the November 15th Earth
and Planetary Science Letters shows. This
atmosphere may have survived for millions of years before being lost to space.
"The terrain would have looked like
a sea of glowing molten rock, with
patches of darker, cooling rocks forming
a fractured crust on top of lava exposed
to the developing atmosphere," says
lead author Debra Needham (NASA

BLACK HOLES

IN BRIEF
Webb Telescope
Launch Delayed
The long-awaited James Webb Space
Telescope (JWST) - successor to the
Hubble Space Telescope - will now
launch between March and June 2019.
Integrating and testing various spacecraft elements, including the five-layered
sunshield, is taking longer than expected
and has forced a roughly 6-month launch
delay from the original October 2018. The
project will nevertheless remain within the
budget that NASA agreed to in 2011. The
telescope and its science instruments are
currently undergoing extensive testing. The
final step will be to integrate the telescope
onto the spacecraft and test the fully assembled observatory before it is launched
to orbit the Sun at the L2 Lagrangian point,
1.5 million km from Earth.
■ MONICA YOUNG

Hawai'i Approves
Megatelescope
A state panel has cleared the way for the
construction of the colossal Thirty Meter
Telescope (TMT) atop Mauna Kea. The
Board of Land and Natural Resources
(BLNR) for the state of Hawai'i announced
its decision on September 29th, after
nearly five months of public hearings. An
earlier BLNR ruling had also approved the
$1.4 billion project, but it was a controversial decision among indigenous Hawaiians, who consider the mountain sacred.

■ JAVIER BARBUZANO

Construction ground to a halt in 2015 after
a string of protests blocked access to
the mountain's summit. The recent ruling
specified 43 special conditions for TMT's
construction, including environmental
protection standards and an agreement
to decommission and remove several
existing telescopes from atop Mauna Kea.
Opponents nevertheless plan to appeal
the BLNR's latest decision to the Hawai'i
Supreme Court.
■ J. KELLY BEATTY

First Official Pluto
Feature Names
The International Astronomical Union (IAU)
has released official names for 14 geological features on Pluto's surface, which were
captured in high resolution during the New
Horizons flyby in 2015. The names follow
four broad themes: pioneering space
missions, historic explorers who crossed
new frontiers, scientists and engineers
who contributed to our knowledge of
Pluto and the Kuiper Belt, and underworld
mythology. The first officially approved
feature names are: Tombaugh Regio,
Burney Crater, Sputnik Planitia, Tenzing
Montes, Hillary Montes, Al-Idrisi Montes,
Djanggawul Fossae, Sleipnir Fossa, Virgil
Fossae, Adlivun Cavus, Hayabusa Terra,
Voyager Terra, Tartarus Dorsa, and Elliot
crater. There is no word yet from the IAU
as to when additional features will receive
official recognition.
■ JAVIER BARBUZANO

* To get astronomy news as it breaks, visit skypub.com/newsblog.

Supermassive Tango
NEW OBSERVATIONS reported in the

October 2017 Nature Astronomy reveal
a double radio source at the center of
Markarian 533 (NGC 7674), a face-on
spiral galaxy in Pegasus. The emission
might come from a tight pair of supermassive black holes.
Preeti Kharb (National Centre for
Radio Astrophysics, India) and colleagues used the Very Long Baseline
Array to resolve two sources at a
frequency of 15 gigahertz, which might
emanate from two supermassive black
holes with a combined mass of 40
million Suns. The putative pair orbit
each other only a light-year apart, the
closest candidate black-hole binary to be
detected via direct imaging.
However, since the VLBI observations only detect the double source at a
single frequency, the spectra are not yet
known, making it difﬁcult to rule out
alternatives. It's possible, for example,
that one source is a black hole, while
the other is the base of a jet rather than
a black hole companion.
But some factors, including the
unusual Z shape of the galaxy's stubby
radio-emitting jets, favor the doubleblack-hole scenario. If future observations conﬁrm the supermassive binary,
it will provide an important perspective
on how such systems form and evolve.
■ MONICA YOUNG

JA N UA RY 2 018 * SK Y & TELESCOPE

N ASA

ABOUT 3½ BILLION years ago, active
volcanoes on the Moon might have
released enough gas to form a transient,
sulfuric atmosphere.

Marshall Space Flight Center). "The
atmosphere would most likely have been
a brownish yellowish haze, due to the
sulfur concentration."
This new vision of Earth's natural satellite comes from an improved analysis of
gases trapped in the Moon rocks gathered
during the Apollo mission, as well as
detailed measurements of lunar features
obtained by recent orbiter missions.
Researchers estimate that, at its
peak, the lunar atmosphere was up to
1½ times as thick as that of present-day
Mars, which has a surface pressure of
0.01 bar - equivalent to 1% of Earth's
atmospheric pressure at sea level.

http://www.skypub.com/newsblog

Sky and Telescope - January 2018

Table of Contents for the Digital Edition of Sky and Telescope - January 2018