NASA’s OSIRIS-REx Begins Earth-Trojan Asteroid Search

A NASA spacecraft begins its search Thursday for an enigmatic class of near-Earth objects known as Earth-Trojan asteroids. OSIRIS-REx, currently on a two-year outbound journey to the asteroid Bennu, will spend almost two weeks searching for evidence of these small bodies.

Trojan asteroids are trapped in stable gravity wells, called Lagrange points, which precede or follow a planet. OSIRIS-REx is currently traveling through Earth’s fourth Lagrange point, which is located 60 degrees ahead in Earth’s orbit around the sun, about 90 million miles (150 million kilometers) from our planet. The mission team will use this opportunity to take multiple images of the area with the spacecraft’s MapCam camera in the hope of identifying Earth-Trojan asteroids in the region.

Although scientists have discovered thousands of Trojan asteroids accompanying other planets, only one Earth-Trojan has been identified to date, asteroid 2010 TK7. Scientists predict that there should be more Trojans sharing Earth’s orbit, but they are difficult to detect from Earth as they appear near the sun on the Earth’s horizon.

“Because the Earth’s fourth Lagrange point is relatively stable, it is possible that remnants of the material that built Earth are trapped within it,” said Dante Lauretta. “So this search gives us a unique opportunity to explore the primordial building blocks of Earth.”

The search commences today and continues through Feb. 20. On each observation day, the spacecraft’s MapCam camera will take 135 survey images that will be processed and examined by the mission’s imaging scientists at the University of Arizona, Tucson. The study plan also includes opportunities for MapCam to image Jupiter, several galaxies, and the main belt asteroids 55 Pandora, 47 Aglaja and 12 Victoria.

Whether or not the team discovers any new asteroids, the search is a beneficial exercise. The operations involved in searching for Earth-Trojan asteroids closely resemble those required to search for natural satellites and other potential hazards around Bennu when the spacecraft approaches its target in 2018. Being able to practice these mission-critical operations in advance will help the OSIRIS-REx team reduce mission risk once the spacecraft arrives at Bennu.

OSIRIS-REx Earth-Trojan

Artist’s conception of the OSIRIS-REx spacecraft at Bennu asteroid. Credit: NASA/GSFC

NASA’s Goddard Space Flight Center provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s observation planning and processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for its Science Mission Directorate in Washington.

For more information on OSIRIS-Rex, visit:

www.nasa.gov/osirisrex  and www.asteroidmission.org


Erin Morton
University of Arizona, Tucson

Nancy Neal Jones
NASA’s Goddard Space Flight Center in Greenbelt, Maryland

Original article here.

Is Saturn Saving the Day?

Jupiter is often cited as Earth’s protector — but Saturn may actually be hero of the day.

Jupiter may not be the “planetary shield” that many scientists make the gas giant out to be. Instead, new simulations suggest that Saturn may play a crucial role in steering asteroids away from Earth.

Saturn Shield

The “Jupiter as a shield” concept arose from a misinterpretation of a 1994 paper by George Wetherill — a planetary scientist at the Carnegie Institution who died in 2006 — says planetary scientist Kevin Grazier. Wetherill’s paper argued that systems with “failed Jupiters” (that is, star systems only with planets of perhaps Uranus and Neptune’s size or smaller) would have more densely populated cometary source regions, and that they “eject a smaller number of comets into interstellar space.”

Grazier, of NASA’s Jet Propulsion Laboratory who has also served as an advisor for “Battlestar: Galactica” and “Gravity,” told Seeker that he tried to replicate Wetherill’s work from 1994. The aim was to see what had changed with the more advanced computing power of today.

Jupiter Shield

The Juno spacecraft (pictured above in an artist’s impression) is visiting the planet right now. Credit: NASA

Grazier found that, through simulations, a typical small body — like an asteroid or comet — between Jupiter and Saturn will get kicked out, but many of them are ejected after they pass into the inner solar system. Further simulations (some dropping Jupiter from the equations, and some dropping Saturn) show that it takes both planets combined to reliably move objects out of the solar system. If only one planet of the two exists, a belt of material is created and only a few small bodies are removed from the solar system.

Grazier’s study argues that Jupiter’s role in the solar system is less of a shield, and more as a bringer of water and other “life-enabling volatiles” to the terrestrial planets and that Saturn has a far bigger role to play when deflecting asteroids and comets.

Read full article here from Elizabeth Howell to Seeker.com

Asteroid Day Press Conference February 14, 2017

asteroid day press conference february 14

Asteroid Day to Announce Increased Global Support and Preview 2017 Events at February 14 Press Conference – Live from Luxembourg City, Berlin, Silicon Valley, Bucharest and London.

TIME: 2.30PM – 3.30PM CET | 08.30AM – 9.30AM EST

Web Access: http://asteroidday.org/pressconference

LONDON (February 8, 2017) – Asteroid Day, a rising global movement to protect our planet, families, communities, and future generations from dangerous asteroids, has scheduled a Global Press Conference, February 14, to announce new partners, sponsors and activities, and to preview Asteroid Day events being organized around the world for June 30, 2017.

Asteroid Day, is held each year on the anniversary of the largest asteroid impact of earth in recent history, the Tunguska event of 1908, which destroyed about 1000 square kilometers in Siberia. The press conference to announce Asteroid Day is being held on the eve of the anniversary of the Chelyabinsk asteroid impact, the most recent asteroid impact, which injured about 1500 individuals in 2013. Asteroid Day was co-founded in 2014 by filmmaker Grig Richters, Silicon Valley business leader Danica Remy, Apollo 9 Astronaut Rusty Schweickart, and Dr. Brian May, astrophysicist and lead guitarist of QUEEN.

United Nations Declaration: On December 7, 2016, the United Nations General Assembly officially recognised Asteroid Day as an annual event, declaring  “30 June International Asteroid Day to observe each year at the international level, the anniversary of the Tunguska impact over Siberia, Russia, on 30 June 1908 and to raise public awareness about the asteroid impact hazard.”

FEBRUARY 14 PRESS CONFERENCE DETAILS

The press conference will be held live at five locations around the world, with media invited to participate in Luxembourg and Berlin. Speakers participating from Cisco TelePresence Centers in Silicon Valley, Bucharest and London are available for one on one interviews, as requested. The full agenda with speakers at each location is listed below. The press conference also will be recorded and available on YouTube and AsteroidDay.org website, courtesy of Cisco, a new corporate partner of Asteroid Day.

SPEAKERS BY LOCATION

RSVP to: pr@asteroidday.org for links to audio and video, as well as to schedule one-on-one interviews.

Luxembourg City – Address: Cisco Systems, Avenue JF Kennedy 46A, 4th Floor, Luxembourg L-1855. RSVP here for to attend.

Berlin – Address: Cisco Systems, Kurfuerstendamm 22 | 12th Floor | Berlin D-10719. RSVP here to attend.

Bucharest, Romania – Cisco Center

San Jose, California – Cisco Center

London – Cisco Center

  • Debbie Lewis, Asteroid Day Risk Management expert; Expert Panel Deputy Chairwoman

100X Declaration

Asteroid Day experts will brief reporters on the progress of major asteroid-related programs related to the organisation’s circulated 100x Declaration, signed by leaders in science, technology, government, entertainment, and citizens around the world. A full list of signatories can be found at AsteroidDay.org

The 100x Declaration targeted three goals:

  • A rapid 100-fold acceleration of the discovery and tracking of Near-Earth Asteroids to 100,000 per year within the next ten years,
  • Employ available technology to detect and track Near-Earth Asteroids that threaten human populations via governments and private and philanthropic organisations,
  • Global adoption of Asteroid Day, heightening awareness of the asteroid hazard and our efforts to prevent impacts, on June 30. This final goal was accomplished with the December 2016 UN Declaration.

RESOURCES FOR JOURNALISTS

MEDIA CONTACTS

US: Diane Murphy (pr@asteroidday.org); Tel. +1310.6588756; EUROPE: Tel: +49 15225672398

Brilliant Fireball Streaks Over U.S.

A brilliant, bright-green meteor blazed through the sky just north of Milwaukee, in U.S., early in the morning of Feb. 6

fireball milwaukee meteor meteorite

Credit: Space Science and Engineering Center (SSEC) and Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison.

The meteor streaked across the sky around 1:25 a.m., and likely landed in the Lake Michigan, according to American Meteor Society (AMS) operations manager Mike Hankey. He said the rock likely was the size of a minivan.

The falling space rock likely burned up in the sky about 10 to 20 miles (16 to 32 kilometers) north of Milwaukee, or about 100 miles (160 km) north of Chicago, according to the AMS.

“We got over 200 eyewitness reports, and they give us the directions where they saw it, and from that we can triangulate everyone’s report,” Hankey said.

Most of the eye-witness reports came from people in and around Chicago and Milwaukee, but reports have also come in from witnesses in Michigan, Indiana, Ohio, Iowa, New York, Kentucky, Minnesota and Ontario, according to the AMS website.

Based on radar data, it is likely that bits of the meteor reached the ground (these are called meteorites), Hankey said. However, the space rocks would have been sprinkled over Lake Michigan, which means they can’t be collected for study, he added.

A meteor large enough to leave meteorites on the ground typically flies over the U.S. about three or four times per year, Hankey said.

The meteor also might have been spotted via radar by the National Weather Service’s Milwaukee office. The office tweeted a radar picture showing the possible location of the meteor over Lake Michigan at 1:31 a.m. CST (0731 GMT). Sarah Marquardt, a meteorologist at the Milwaukee office, told Space.com that the radar instruments likely identified the space rock as it broke up into very small pieces. The radar instruments are designed to detect primarily water droplets, but the radar showed that the object or objects in that area were not made of ice or water, she said.

Full articles here, from Space.com and here from CBS Chicago.