Deep in the heart of the spiral Milky Way galaxy, a hot vortex of matter swirls around a black hole more than a million times as massive as the sun.
Many galaxies, perhaps all, contain such a monster in the middle. These supermassive black holes sustain themselves by swallowing stars, planets, asteroids, comets and clouds of gas that wander by the crowded galactic core
Cosmic Bow Shocks
Bow shocks form across the universe, and studying bow shocks can reveal many cosmic secrets
Astrophysics Big Questions About Small Worlds
Small Worlds hold keys to questions about our solar system and the origin of life on Earth.
Scientists who study the solar system tend to ask big questions: How was our solar system formed? Where did the building blocks of life come from? What hazards from above threaten life on our planet? To find answers, theyre looking more and more at small worlds.
What are small worlds? Asteroids for sure. Comets too. Also the many small satellites or moons that orbit large planets as well as the icy worlds at the distance of Pluto and beyond. Some have combined, only to be broken apart later by collisions and tidal forces. Others have gone largely untouched since the dawn of the solar system. Some carry water and organic compounds, others are almost entirely composed of metal. And all hold keys to questions about our solar system and the origin of life on Earth.
Water is key to life as we know it. Learning where water is found in our solar system provides pieces to the puzzle of understanding the origins of life. New Horizons recently surprised us by discovering a large abundance of water ice at Pluto. More surprises are in store, as New Horizons transmits the data from its January 1, 2019 flyby of the Kuiper Belt object 2014 MU69 back to Earth!
Small worlds can be found in a wide range of locations across the solar system, from the inner solar system all the way out to the Kuiper Belt. When they are studied together, these remnants of the early solar system can help tell the story of solar system formation.
Dawn recently completed a mission to the Main Asteroid Belt, visiting the dwarf planet Ceres and the Belts largest asteroid, Vesta. OSIRIS-REx has arrived at Bennu, a near-Earth asteroid about 1650 feet (500 m) across, and will return to Earth in 2023 with a sample so scientists can begin to understand Bennus origin and history. The Lucy mission will be traveling to six trojan asteroids, trapped in the orbit of Jupiter. These objects are the only remaining unexplored population of small worlds in the solar system. The Psyche mission will be visiting a metal object in the Main Asteroid Belt that could be the remnant core of a proto-planet similar in size to Vesta!
While those missions travel to their individual targets, NEOWISE, a repurposed space telescope in low-Earth orbit, has made infrared measurements of hundreds of near-Earth objects and tens of thousands of other small worlds in the solar system. These diverse worlds offer insights into how our solar system formed and evolved.
This is not your grandparents solar system and things are not as orderly as we once believed.
The data weve gleaned from these objects so far have changed the way we think about the origin of the planets. For example, the small worlds in the Kuiper Belt are leading us to think that Uranus and Neptune formed much closer to the Sun than where they reside now, then gradually moved to their current orbits.
The biggest misperception about small worlds? Their distance to each other. In the movies, they always show an asteroid belt with millions of rocks almost touching each other, whereas in reality there is much more empty space. You have to travel hundreds of thousands of miles to get from one asteroid to another.
Yet scientists are also looking closer to home. Determining the orbits and physical characteristics of objects that might impact Earth is critical to understanding the consequences of any such impact; and responding to an actual impact threat, if one is ever discovered. knows of no asteroid or comet currently on a collision course with Earth. But, to prepare for that scenario is developing the Double Asteroid Redirection Test or DART mission as the first demonstration of the kinetic impact technique that could be used to change the motion of a hazardous asteroid away from Earth.
Effects Of The Solar Wind
The wind speed of a devastating Category 5 hurricane can top over 150 miles per hour (241km/hour.) Now imagine another kind of wind with an average speed of 0.87 million miles per hour (1.4 million km/hour.)
Welcome to the wind that begins in our Sun and doesn't stop until after it reaches the edge of the heliosphere: the solar wind.
The corona is the Sun's inner atmosphere - the brightness that can be seen surrounding an eclipsed Sun - and home to the continually expanding solar wind. Right now, the Parker Solar Probe - launched in 2018, is orbiting the Sun and will get as close as 3.83 million miles (6.16 million km) of the Sun's surface. Parker is gathering new data about the solar particles and magnetic fields that comprise the solar wind. More specifically, two of its main goals are to examine the energy that heats the corona and speeds up the solar wind, and determine the structure of the wind's magnetic fields.
While many theories describe the solar wind's history, this is what we do know: The solar wind impacting Earth's magnetosphere is responsible for triggering those majestic auroras typically seen at locations close to our north and south poles. In some cases it can also set off space weather storms that disrupt everything from our satellites in space, to ship communications on our oceans, to power grids on land.
To say in more detail , how the solar wind disrupts our magnetosphere: As the wind flows toward Earth, it carries with it the Sun's magnetic field. It moves very fast, then smacks right into Earth's magnetic field. The blow causes a shock to our magnetic protection, which can result in turbulence.
There is another reason to study the solar wind and its properties - the solar wind is part of a larger space weather system that can affect astronauts and technology. We not only have to ensure our astronauts are protected from the harmful effects of radiation.
We have to protect our equipment too. So, we've already found aluminum to be a good shield to protect our crafts from many energetic particles. But there are also faster particles that travel at 80% of the speed of light, which can cause havoc with parts of a spacecraft. They can smash into and damage solar panels, disrupt electronics, or affect electric currents that flow along power grids.
So, we're currently conducting tests with small pieces of technology to study how well they can survive in intense radiation areas.
Knowing more about the effects of the solar wind is not only important to those of us who live on Earth. It will be critical to know how to mitigate its effects once our astronauts travel back to the Moon and beyond for extended periods of time.
If the Sun sneezes, Earth catches a cold, because we always feel the impact of what happens on the Sun thanks to the solar wind.
Get blown away by the science behind the solar wind at MXPlank.com
