Radioastronomers Measure Sizes Of Distant Planets

Scientists at the Max-Planck-Institute for Radioastronomy (MPIfR) in Bonn were able to determine the diameters of four of the largest and most distant minor planets in our solar system. The largest of them was discovered last June by planetary scientists of the California Institute of Technology (Caltech), who named their object “Quaoar” after a creation myth of the Californian native Tongva people. The radio observations of the Bonn astronomers and their Californian colleagues show that Quaoar has a diameter of 1250 km, making it the largest object discovered in the solar system since the discovery of Pluto in 1930. Minor planets are discovered as slowly moving unresolved sources in optical sky photographs taken with astronomical telescopes. Drs. Frank Bertoldi and Wilhelm Altenhoff from the MPIfR recently used the IRAM 30-meter telescope in Spain to measure the thermal radiation of four of the optically brightest minor planets. From the measured intensity they could derive their sizes, which range between 700 and 1200 km (see table below).

On October 7 their Caltech colleagues presented their discovery of Quaoar at the annual meeting of the Planetary Sciences Division of the American Astronomical Society, which is held in Birmingham, Alabama. There they also present a direct size measurement of Quaoar from optical images obtained with the Hubble Space Telescope. This unique and first such observation confirms the prior radio size measurement.

The four minor planets are members of a ring of some 100,000 objects in the outskirts of the solar system, beyond Pluto at distances over 4 billion km from the sun, over 30 times the distance between earth and sun. The objects in this “Kuiper belt” circle the sun in stable orbits with periods of about 300 years. In the mid of last century, the existence of a ring of small planetisemals was first suggested by the astronomers Kenneth Edgeworth (1880-1972) and Gerard P. Kuiper (1905-1973), but the first discovery of an “Edgeworth-Kuiper belt object” (EKO) was not until 1992. By now, over 550 EKOs are known.

 

Comments are closed.

Nightingale CXO 6200 Memory Foam, New Headrest, Lumbar Support Ergo Office Chair picture

Nightingale CXO 6200 Memory Foam, New Headrest, Lumbar Support Ergo Office Chair

$440.00



NEW Siemens 6ES7 953-8LL20-0AA0 6ES7953-8LL20-0AA0 Memory Card picture

NEW Siemens 6ES7 953-8LL20-0AA0 6ES7953-8LL20-0AA0 Memory Card

$356.05



Nightingale CXO 6200 Memory Foam Seat, Mesh Back, Lumbar Support, Advanced Arms picture

Nightingale CXO 6200 Memory Foam Seat, Mesh Back, Lumbar Support, Advanced Arms

$340.00



Reliance Electric 0-57413-E Communication Memory Module Used With Warranty picture

Reliance Electric 0-57413-E Communication Memory Module Used With Warranty

$599.99



5 - DDR RAM Memory Module OEM-Bulk Shipping Trays DUMS PC-Server DIMM - Fits 250 picture

5 - DDR RAM Memory Module OEM-Bulk Shipping Trays DUMS PC-Server DIMM - Fits 250

$41.60



🔥🔥 2 Pack x Genuine SanDisk 2GB SD CARD CLASS 2 SDHC Flash Memory Card 🔥🔥 picture

🔥🔥 2 Pack x Genuine SanDisk 2GB SD CARD CLASS 2 SDHC Flash Memory Card 🔥🔥

$15.99



HNNIX PC3200U-30330 RAM MEMORY CARD_HNNIX PC3200U 30330 picture

HNNIX PC3200U-30330 RAM MEMORY CARD_HNNIX PC3200U 30330

$79.99



Allen Bradley 1GB SD Memory Card       1784-SD1 picture

Allen Bradley 1GB SD Memory Card 1784-SD1

$19.00



Allen-Bradley 1784-SD2 /A 2GB Memory Module picture

Allen-Bradley 1784-SD2 /A 2GB Memory Module

$50.00



Allen-Bradley 1772-MEB Memory Module picture

Allen-Bradley 1772-MEB Memory Module

$360.31



Powered by WordPress. Designed by WooThemes