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NASA Space Place – Comet Campaign: Amateurs Wanted

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in January, 2017.

By Marcus Woo

2013february2_spaceplaceIn a cosmic coincidence, three comets will soon be approaching Earth—and astronomers want you to help study them. This global campaign, which will begin at the end of January when the first comet is bright enough, will enlist amateur astronomers to help researchers continuously monitor how the comets change over time and, ultimately, learn what these ancient ice chunks reveal about the origins of the solar system.

Over the last few years, spacecraft like NASA’s Deep Impact/EPOXI or ESA’s Rosetta (of which NASA played a part) discovered that comets are more dynamic than anyone realized. The missions found that dust and gas burst from a comet’s nucleus every few days or weeks—fleeting phenomena that would have gone unnoticed if it weren’t for the constant and nearby observations. But space missions are expensive, so for three upcoming cometary visits, researchers are instead recruiting the combined efforts of telescopes from around the world.

“This is a way that we hope can get the same sorts of observations: by harnessing the power of the masses from various amateurs,” says Matthew Knight, an astronomer at the University of Maryland.

By observing the gas and dust in the coma (the comet’s atmosphere of gas and dust), and tracking outbursts, amateurs will help professional researchers measure the properties of the comet’s nucleus, such as its composition, rotation speed, and how well it holds together.

The observations may also help NASA scout out future destinations. The three targets are so-called Jupiter family comets, with relatively short periods just over five years—and orbits that are accessible to spacecraft. “The better understood a comet is,” Knight says, “the better NASA can plan for a mission and figure out what the environment is going to be like, and what specifications the spacecraft will need to ensure that it will be successful.”

The first comet to arrive is 41P/Tuttle–Giacobini–Kresák, whose prime window runs from the end of January to the end of July. Comet 45P/Honda–Mrkos–Pajdušáková will be most visible between mid-February and mid-March. The third target, comet 46P/Wirtanen won’t arrive until 2018.

Still, the opportunity to observe three relatively bright comets within roughly 18 months is rare. “We’re talking 20 or more years since we’ve had anything remotely resembling this,” Knight says. “Telescope technology and our knowledge of comets are just totally different now than the last time any of these were good for observing.”

For more information about how to participate in the campaign, visit www.psi.edu/41P45P46P.

Want to teach kids about the anatomy of a comet? Go to the NASA Space Place and use Comet on a Stick activity! spaceplace.nasa.gov/comet-stick/

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Caption: An orbit diagram of comet 41P/Tuttle-Giacobini-Kresak on February 8, 2017—a day that falls during the comet’s prime visibility window. The planets orbits are white curves and the comet’s orbit is a blue curve. The brighter lines indicate the portion of the orbit that is above the ecliptic plane defined by Earth’s orbital plane and the darker portions are below the ecliptic plane. This image was created with the Orbit Viewer applet, provided by the Osamu Ajiki (AstroArts) and modified by Ron Baalke (Solar System Dynamics group, JPL). ssd.jpl.nasa.gov/sbdb.cgi?orb=1;sstr=41P

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

NASA Space Place – Hubble’s Bubble Lights Up The Interstellar Rubble

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in June, 2016.

By Dr. Ethan Siegel

2013february2_spaceplaceWhen isolated stars like our Sun reach the end of their lives, they’re expected to blow off their outer layers in a roughly spherical configuration: a planetary nebula. But the most spectacular bubbles don’t come from gas-and-plasma getting expelled into otherwise empty space, but from young, hot stars whose radiation pushes against the gaseous nebulae in which they were born. While most of our Sun’s energy is found in the visible part of the spectrum, more massive stars burn at hotter temperatures, producing more ionizing, ultraviolet light, and also at higher luminosities. A star some 40-45 times the mass of the Sun, for example, might emits energy at a rate hundreds of thousands of times as great as our own star.

The Bubble Nebula, discovered in 1787 by William Herschel, is perhaps the classic example of this phenomenon. At a distance of 7,100 light years away in the constellation of Cassiopeia, a molecular gas cloud is actively forming stars, including the massive O-class star BD+60 2522, which itself is a magnitude +8.7 star despite its great distance and its presence in a dusty region of space. Shining with a temperature of 37,500 K and a luminosity nearly 400,000 times that of our Sun, it ionizes and evaporates off all the molecular material within a sphere 7 light years in diameter. The bubble structure itself, when viewed from a dark sky location, can be seen through an amateur telescope with an aperture as small as 8″ (20 cm).

As viewed by Hubble, the thickness of the bubble wall is both apparent and spectacular. A star as massive as the one creating this bubble emits stellar winds at approximately 1700 km/s, or 0.6% the speed of light. As those winds slam into the material in the interstellar medium, they push it outwards. The bubble itself appears off-center from the star due to the asymmetry of the surrounding interstellar medium with a greater density of cold gas on the “short” side than on the longer one. The blue color is due to the emission from partially ionized oxygen atoms, while the cooler yellow color highlights the dual presence of hydrogen (red) and nitrogen (green).

The star itself at the core of the nebula is currently fusing helium at its center. It is expected to live only another 10 million years or so before dying in a spectacular Type II supernova explosion.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

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Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA), of the Bubble Nebula as imaged 229 years after its discovery by William Herschel.

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

NASA News – NASA’s Hubble Finds Dwarf Galaxies Formed More Than Their Fair Share of Universe’s Stars

From NASA News: RELEASE: 14-173 – 19 June 2014

They may be little, but they pack a big star-forming punch. New observations from NASA’s Hubble Space Telescope show small galaxies, also known as dwarf galaxies, are responsible for forming a large proportion of the universe’s stars.

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Click for a full-size version. Hiding among these thousands of galaxies are faint dwarf galaxies residing in the early universe, between 2 and 6 billion years after the big bang, an important time period when most of the stars in the universe were formed. Some of these galaxies are undergoing starbursts. Image Credit: NASA and ESA

Studying this early epoch of the universe’s history is critical to fully understanding how these stars formed and how galaxies grew and evolved 3.5 to 6 billion years after the beginning of the universe. The result supports a decade-long investigation into whether there is a link between a galaxy’s mass and its star-forming activity, and helps paint a consistent picture of events in the early universe.

“We already suspected these kinds of galaxies would contribute to the early wave of star formation, but this is the first time we’ve been able to measure the effect they actually had,” said Hakim Atek of the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, lead author of the study published in the June 19 online issue of The Astrophysical Journal. “They appear to have had a surprisingly huge role to play.”

Previous studies of star-forming galaxies were restricted to the analysis of mid- or high-mass galaxies, leaving out the numerous dwarf galaxies that existed in this era of prolific star formation. Astronomers conducted a recent study using data from Hubble’s Wide Field Camera 3 (WFC3) to take a further and significant step forward in understanding this formative era by examining a sample of starburst galaxies in the young universe. Starburst galaxies form stars at a furiously fast rate, far above what is considered by experts to be a normal rate of star formation.

The infrared capabilities of WFC3 have allowed astronomers to finally calculate how much these low-mass dwarf galaxies contributed to the star population in our universe.

“These galaxies are forming stars so quickly they could actually double their entire mass of stars in only 150 million years — an incredibly short astronomical timescale,” adds co-author Jean-Paul Kneib, also of EPFL.

Researchers say such massive growth would take most “normal” galaxies 1 to 3 billion years.

In addition to adding new insight to how and where the stars in our universe formed, this latest finding may also help to unravel the secrets of galactic evolution. Galaxies evolve through a jumble of complex processes. As galaxies merge, they are consumed by newly-formed stars that feed on their combined gases, and exploding stars and supermassive black holes emit galactic material – a process that depletes the mass of a galaxy.

It is unusual to find a galaxy in a state of starburst, which suggests to researchers starburst galaxies are the result of an unusual incident in the past, such as a violent merger.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.

For images and more information about Hubble, visit: www.nasa.gov/hubble and hubblesite.org/news/2014/25