Sky & Telescope - April 2022 - 8

JWST LAUNCH: ESA / CNES / ARIANESPACE; PARKER SOLAR PROBE
ILLUSTRATION: NASA / JOHNS HOPKINS APL / BEN SMITH
NEWS NOTES
The James Webb Space Telescope lifts off
early morning on December 25th.
to the telescope's operations, as it helps
cool the observatory down to below 50K
(-223°C or -370°F). The next crucial
step followed days after, as 132 actuators
helped unfurl the 18 gold-plated
beryllium mirror segments that make
up the telescope's 6.6-meter (21.7-foot)
primary mirror. On January 8th, NASA
announced that the deployment phase
was complete. Now, the team will commission
the telescope and its instruments
for about five months after the
telescope arrives at L2. Science operations
should begin mid-year.
JWST will push forward our underSPACE
The
James Webb Space Telescope Launches
AT LAST! After more than two decades
of development, cost overruns, a 2005
redesign, and brushes with Congress,
the James Webb Space Telescope (JWST)
launched on an Ariane 5 rocket on
December 25th from the Guiana Space
Center in French Guiana.
The first and second stages set JWST
on a path toward a halo orbit around
the Sun-Earth L2 Lagrange point,
1.5 million kilometers (1 million miles)
SOLAR SYSTEM
Parker Solar Probe " Touches " the Sun
NASA'S PARKER SOLAR PROBE
(S&T: Nov. 2020, p. 20) entered our
star's atmosphere on April 28, 2021,
" touching " the surface of the Sun. The
probe slipped past a critical boundary
known as the Alfvén surface, entering a
region of space where the Sun's crackling
magnetic field has a tight hold on
the plasma and governs its movements.
The probe actually entered this
magnetized atmosphere a total of
three times, explains Justin Kasper
(BWX Technologies, Inc. and University
8
APRIL 2022 * SKY & TELESCOPE
of Michigan), principal investigator
of the probe's particle-detecting Solar
Wind Electrons Alphas and Protons
(SWEAP) instruments. Kasper led a
study on the crossings in the December
Physical Review Letters.
The first time Parker passed the
Alfvén surface, it flew through the solar
atmosphere for about five hours. Even
as it continued flying toward the Sun,
 In this artist's concept, the Parker Solar Probe
hovers above a hilly boundary known as the
Alfvén surface.
from Earth in the anti-sunward direction.
Mission controllers reported the
payload in good health post-launch.
The infrared space telescope will
take 30 days to enter its final orbit, but
deployment occurred while it was still
en route. On January 4th, the team
finished deploying the telescope's tennis
court-size sunshield. This structure,
which consists of five layers of a lightweight
material called Kapton, is critical
standing of the universe at wavelengths
from 0.6 to 28.3 microns, performing
observations that can only be done in
space. A joint project between NASA,
the Canadian Space Agency, and the
European Space Agency, JWST will
answer key questions for a new generation
of astronomers. It will witness
the formation of galaxies in the early
universe, study the birth of stars and
planetary systems, and explore exoplanet
atmospheres, as well as observe
solar system bodies.
While JWST has a minimum lifetime
of five years, NASA issued a statement
post-launch saying that the mission has
enough fuel to support " significantly
more than a 10-year science lifetime. "
¢DAVID DICKINSON
Sky & Telescope - April 2022

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