NASA | JWST Feature – Planetary Evolution

sound effects sound effects The places where The places where stars and planets are born are
among the galaxy’s most
beautiful locales. These cosmic
landscapes change as new
generations of stars light up and disperse
their birth cloud. But the
youngest stars seen here are already
perhaps a million years old. Hardly toddlers.Stars and
planets inside vast, cold clouds of gas
and dust, such as these pillars
imaged by the Hubble Space
Telescope. The dust is so thick we can’t
see the infant stars inside. At least, not with visible
light. With infrared light, Hubble can
see through all but the
thickest dust. Yet it’s in those dense knots
that the youngest stars are forming. To peer
inside them, astronomers need the James Webb
Space Telescope. With a mirror larger than Hubble’s and
performance optimized for the
infrared, Webb will give astronomers
their closest look yet at
stellar birth. We’re flying through a computer
model that represents
astronomers’ best ideas about the star formation
process. Redder colors indicate thicker
dust. The temperature? Less
than 400 degrees below zero Fahrenheit –
or less than 240 degrees below zero celsius. That pinwheel ahead is a
protostar, perhaps 10,000 years old. Protostars
arise when a dense knot of dust less than a
light-year across collapses, but the details of the process
are not well known. Elsewhere in the cloud, another protostar is
preparing to build planets. As the cloud that created the
protostar collapsed, it
flattened into a disk. The disk we see here is
600 times the size of of Earth’s orbit around the
sun. If placed in our solar system, it would extend far
beyond the planets. In this computer model, the
disk continues to accumulate
gas and dust from its surroundings for
thousands of years. Eventually, the disk fragments, producing
dense, bright structures. These may become sites where
giant planets form. Later, during another phase of
construction, smaller, Earth-size planets may take
shape. At least, that’s what
scientists think happens. It will take the Webb
telescope’s keen infrared eye
to see what’s really going on in the cold heart of
stellar nurseries. music and sound effects beep beep


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