Rogue asteroid a fifth bigger than thought, says ESA



Agence France Presse

Published — Friday 11 January 2013

Last update 11 January 2013 12:44 am

| نسخة PDF Print News | A A

PARIS: An asteroid believed to pose a remote risk of colliding with Earth this century is 20 percent bigger than previously thought, the European Space Agency (ESA) said on Wednesday.
In a press release, ESA said its Herschel deep-space telescope had scanned a space rock called 99942 Apophis last weekend as it headed toward its closest flyby with our planet in years on Wednesday.
Previous estimates bracketed the asteroid’s average diameter at 270 meters (877 feet) give or take 60m (195 feet), representing a mass that would equal the energy release of a 506-megaton bomb, according to NASA figures.
In a two-hour observation, Herschel returned a diameter of 325m (1,056 feet), with a range of 15m (48.75 feet) either way, ESA said.
“The 20-percent increase in diameter, from 270 to 325m (877 to 1,056 feet), translates into a 75-percent increase in our estimates of the asteroid’s volume or mass,” said Thomas Mueller of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, who led the data analysis.
Named after the god of evil and darkness in Egyptian mythology, Apophis sparked a scare when it was first detected in 2004. Early calculations suggested a 2.7-percent probability of collision in 2029, the highest ever for an asteroid, but the risk was swiftly downgraded after further observations.
A distance of 35,000 kilometers (22,500 miles), meaning it will flit past inside the orbit of geostationary satellites, is the latest estimate for 2029, ESA said.
There remains a tiny impact risk of about one in 250,000 on April 13, 2036, when it will pass even closer to Earth, according to NASA’s Jet Propulsion Laboratory (JPL). Astronomers hope that Wednesday’s flyby, with Apophis due to zip past at a distance of some 14.5 million kilometers (nine million miles), will help them fine tune the 2029 and 2036 estimates.
Herschel, using thermal sensors, also found that Apophis is somewhat darker than thought, ESA added.
Only 23 percent of light that falls on it is reflected, and the rest is absorbed by the asteroid. Previous estimates of this reflectivity, known as albedo, were in the order of 33 percent.
This finding is important because asteroids experience something called the Yarkovsky effect, or an increase in thrust that comes from alternate heating and cooling as the rock slowly turns in space.
Over time, this momentum can change the body’s trajectory as it moves through the Solar System.
On Feb. 15, a 57-meter (185-feet) asteroid, 2012 DA14, will skim the planet at just 34,500 kilometers (21,600 miles), making the narrowest approach so far of any detected asteroid.

What's happening around Saudi Arabia

Custodian of the Two Holy Mosques King Salman prays inside the historic Quba Mosque in Madinah. The king was accompanied by Prince Muqrin, Sheikh Abdul Rahman Al-Sudais, head of the Presidency of the Two Holy Mosques and Prince Sultan bin Salman, ch...
JEDDAH: Shop rentals at certain malls have risen by 200 percent, with this cost likely to be passed on to the consumer, the Jeddah Chamber of Commerce and Industry (JCCI) said here recently. Muhammad Al-Shehri, chairman of the JCCI’s textiles and gar...
JEDDAH: People with special needs can now visit a park that has dedicated services for them.Jeddah Mayor Hani Abu Ras opened Al-Erada Park in Al-Salama district on Prince Sultan Street on Thursday.“The Kingdom provides special care for people with di...
JEDDAH: Is involvement in social media the right thing or wrong, particularly in the month of Ramadan? There is a difference of opinion with some arguing that it eats into the time that should be spent praying while some backing it for its religious...
RIYADH: The Argentine government has thanked the Kingdom for previously hosting its Umrah pilgrims for free.“They were part of a group invited by then Custodian of the Two Holy Mosques King Abdullah,” said Ambassador Jaime Sergio Cerda on Thursday.“T...
RIYADH: The Ministry of Education’s counseling department has approved the Rifq Program for the physical and psychological well-being of students.Nabil Mohammad Al-Budair, director of counseling for boys, said the program aims to reduce violence in p...
RIYADH: Sales of fireworks at public markets and main roads in Riyadh have increased during Ramadan, despite the Ministry of Commerce and Industry announcing a SR5,000 reward for anyone providing information about warehouses storing these dangerous i...
RIYADH: The General Organization for Social Insurance (GOSI) has reported that there were 69,241 work-related accidents in 2014, with expatriates making up 65,509 or 94.6 percent and Saudis 3,732.The accidents were in nine sectors with building and c...
JEDDAH: The Health Ministry’s expenditures over the past five years increased from SR29.29 billion to SR53.73 billion, an increase of about 83 percent.According to a study detailing the ministry’s expenditures between 2008 and 2012 issued by the mini...
RIYADH: Five people from the southern Indian state of Kerala were killed in a road accident at Salwa near Dammam in the Eastern Province early Thursday morning.Manoj Kumar, community welfare attache at the Indian Embassy, told Arab News that the vict...
MAKKAH: The government has deployed eight helicopters over Makkah to track the movement of vehicles and people, and assist in security tasks and medical evacuations.Maj. Gen. Mohammad Al-Harbi, commander of the Interior Ministry’s aviation security d...
JAZAN: A Yemeni woman (A.M.) has once again experienced freedom and a renewed sense of hope in life after reuniting with her family last week on her release from Jazan General Prison, where she spent six years on charges of murder of a citizen in the...
RIYADH: A delegation from the Kingdom recently visited the United Arab Emirates (UAE) to explore that country’s successful experience in tourism, in a bid to further develop the sector. Saudi Arabia has been making all-out efforts to promote tourism,...
RIYADH: The Justice Ministry has appointed 1,145 candidates for jobs in the judiciary and urged them to complete the requirements for their final appointment. The candidates in the sixth and fourth ranks are requested to fulfill employment prerequisi...
JEDDAH: Four thousand Djibouti workers are expected to arrive in the Kingdom over the next few months following the labor pact signed between the two countries last month.Speaking to a local publication recently, Djibouti Ambassador Diaa Eddin Saeed...

Stay Connected

Facebook