Space Observatory "Herschel" performed new observations of asteroid Apophis during his approach to Earth last weekend. Evidence suggests that the object is greater than previously thought, and has less reflective.

(99942) Apophis (previously, it was designated as 2004 MN4) received in the media nickname "doomsday Asteroid", since the first observations made shortly after its opening in 2004, indicated the possibility of collision with the Earth in April 2029 with the probability of 2.7%. In the future the probability of a catastrophe was excluded, but it is believed that the body will be held in 36 thousand kilometers from the Earth, that is closer than the orbit of geostationary satellites.

The asteroid will return to our surroundings in 2036, but how close fit, unknown, for convergence in 2029 significantly alter its orbit. Therefore, information on the physical parameters of Apophis is now especially important - otherwise there will be no forecast of the trajectory.

"Herschel" observed the asteroid in about two hours, when he came to Earth somewhere 14.5 million km (slightly less than one-tenth of the distance to the Sun). It should be noted that this is only the second of near-Earth object that has received attention "Gershel". Moreover, these were the most rapid observations in the history of space telescopes, for Apophis was moving with the speed of 205 seconds of arc per hour from the point of view of our hero.

The result was the first thermal infrared observations of Apophis on different wavelengths, which together with optical measurements helped to improve the assessment of characteristics of the object. According to data obtained earlier, the average diameter of the asteroid is 270 ± 60 m "Herschel" gave more precise numbers - 325 ± 15 PM

The increase in diameter of 20% means 75% increase of the volume and mass of the asteroid.

Analysis of heat from the Apophis, allowed to obtain a new estimate albedo - 0,23. In other words, 23% of the sunlight that falls on the surface of the asteroid, is reflected and the rest is absorbed and warms it. According to the previous data, this indicator is equal to 0.33.

Knowledge of the thermal properties of the asteroid allows you to understand how its orbit may change as close approach to the Sun in accordance with effect arlovskogo.