Heart and Soul Nebulae
peak
by Matias Alonso Revelli
This surreal timelapse, landscape, panorama spans predawn, blue hour, and sunrise skies. Close to the start of spring in the northern hemisphere, this amazing lapse was captured between 4:30 and 7:00 am from a location overlooking northern New Mexico's Rio Grande Valley. In tracked images of the night sky just before twilight begins, the Milky Way is cast across the southern (right) edge of the panoramic frame. Toward the east, a range of short and long exposures resolves the changing brightness as the Sun rises over the distant peaks of the Sangre de Cristo Mountains. In between, exposures made during the spring morning's tantalizing blue hour are used to blend the night sky and sunrise over the high desert landscape.
Image Credit & Copyright: Paul Schmit
星河坠落 By - 眯眼缄默
Clearest image of Phobos ever taken, Moon of Mars
Bright Planetary Nebula NGC 7027 from Hubble Image Credit: NASA, ESA, Joel Kastner (RIT) et al.; Processing: Alyssa Pagan (STScI)
Explanation: What created this unusual planetary nebula? NGC 7027 is one of the smallest, brightest, and most unusually shaped planetary nebulas known. Given its expansion rate, NGC 7027 first started expanding, as visible from Earth, about 600 years ago. For much of its history, the planetary nebula has been expelling shells, as seen in blue in the featured image. In modern times, though, for reasons unknown, it began ejecting gas and dust (seen in red) in specific directions that created a new pattern that seems to have four corners. These shells and patterns have been mapped in impressive detail by recent images from the Wide Field Camera 3 onboard the Hubble Space Telescope. What lies at the nebula’s center is unknown, with one hypothesis holding it to be a close binary star system where one star sheds gas onto an erratic disk orbiting the other star. NGC 7027, about 3,000 light years away, was first discovered in 1878 and can be seen with a standard backyard telescope toward the constellation of the Swan (Cygnus).
∞ Source: apod.nasa.gov/apod/ap200630.html
NGC 7023, Iris Nebula
Scorpio, Milky Way and Jupiter
Jupiter
It’s no secret the Sun affects us here on Earth in countless ways, from causing sunburns to helping our houseplants thrive. The Sun affects other objects in space, too, like asteroids! It can keep them in place. It can move them. And it can even shape them.
Asteroids embody the story of our solar system’s beginning. Jupiter’s Trojan asteroids, which orbit the Sun on the same path as the gas giant, are no exception. The Trojans are thought to be left over from the objects that eventually formed our planets, and studying them might offer clues about how the solar system came to be.
Over the next 12 years, NASA’s Lucy mission will visit eight asteroids—including seven Trojans— to help answer big questions about planet formation and the origins of our solar system. It will take the spacecraft about 3.5 years to reach its first destination.
How does the Sun affect what Lucy might find?
Credits: Astronomical Institute of CAS/Petr Scheirich
The Sun makes up 99.8% of the solar system’s mass and exerts a strong gravitational force as a result. In the case of the Trojan asteroids that Lucy will visit, their very location in space is dictated in part by the Sun’s gravity. They are clustered at two Lagrange points. These are locations where the gravitational forces of two massive objects—in this case the Sun and Jupiter—are balanced in such a way that smaller objects (like asteroids or satellites) stay put relative to the larger bodies. The Trojans lead and follow Jupiter in its orbit by 60° at Lagrange points L4 and L5.
The Sun can move and spin asteroids with light! Like many objects in space, asteroids rotate. At any given moment, the Sun-facing side of an asteroid absorbs sunlight while the dark side sheds energy as heat. When the heat escapes, it creates an infinitesimal amount of thrust, pushing the asteroid ever so slightly and altering its rotational rate. The Trojans are farther from the Sun than other asteroids we’ve studied before, and it remains to be seen how sunlight affects their movement.
The Sun can break asteroids, too. Rocks expand as they warm and contract when they cool. This repeated fluctuation can cause them to crack. The phenomenon is more intense for objects without atmospheres, such as asteroids, where temperatures vary wildly. Therefore, even though the Trojans are farther from the Sun than rocks on Earth, they’ll likely show more signs of thermal fracturing.
Like everything in our solar system, asteroids are battered by the solar wind, a steady stream of particles, magnetic fields, and radiation that flows from the Sun. For the most part, Earth’s magnetic field protects us from this bombardment. Without magnetic fields or atmospheres of their own, asteroids receive the brunt of the solar wind. When incoming particles strike an asteroid, they can kick some material off into space, changing the fundamental chemistry of what’s left behind.
Follow along with Lucy’s journey with NASA Solar System on Instagram, Facebook, and Twitter, and be sure to tune in for the launch at 5 a.m. EDT (09:00 UTC) on Saturday, Oct. 16 at nasa.gov/live.
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By Reddit user: u/DanielJStein