Factsheet

ALMA, the largest radio telescope in the world

21

Countries participate in the project, in Europe, North America, East Asia and Chile.

2003

The year construction began

1400

Million dollars was the total cost to build ALMA

2900

Meters above sea level is the altitude where the ALMA Operations Support Facilities (OSF or camp) are located

40

Minutes by car separate ALMA from the city of San Pedro de Atacama

¼

Of its total capacity was what ALMA operated with when it started its scientific observations in September 2011 (a year and a half before its inauguration on March 13, 2013)

10

Times more details than the Hubble space telescope images can be seen in ALMA images

10

Milliarcseconds maximum angular resolution (equivalent to a basketball hoop on the Moon)

1 TB

Of scientific data produced daily

+500

Scientific publications in its first 5 years of operations

Antennas

66

Antennas (54 with 12 meter diameters and 12 with 7 meter diameters)

6492

m2 total surface area of radio wave data collection (each 12-m antenna has 113 m2 and each 7-m antenna has 38.5 m2)

10

receiver bands (table with bands)

16

Kilometers of maximum baseline (separation) between antennas

0.6

Arcseconds of angular precision, like aiming at a golf ball from 15 kilometers away

25

Micrometers is the precision of the reflector surface (thinner than a sheet of paper)

-269

ºC is the temperature that the receivers must be kept at (only 4 ºC above absolute zero) to ensure the greatest sensitivity of all of these types of receivers

4 + 12

Antennas make up the Morita Array, also known as the Atacama Compact Array (ACA – four antennas with 12 meter diameters and twelve antennas with 7 meter diameters)

100

Tons are how much each antenna weighs and 135 tons the transporters that move them

8

Hours are how many it takes to move an antenna from the OSF to the AOS: 1.5 to load, 5 to transport and 1.5 to unload

Chajnantor

5000

Meters above sea level is the altitude of the Chajnantor —‘take-off site’ in the Atacameño language Ckunza— plateau, where ALMA is located. The highest astronomic site for a project of this size and one of the driest in the world

40

ºC difference between the maximum daytime and nighttime temperatures

160

Km/h maximum wind speed

50

Years land concession granted for the area where ALMA is located

The Correlator

1

The supercomputer operating at the highest altitude in the world

200

Kilometers of fiber opticconnect ALMA to the city of Calama, where it connects to Antofagasta, Santiago and the rest of the world

17

PetaOperations (17 trillion operations per second), equivalent to billions of dollars in personal computers to make the necessary calculations. This is the fastest computer ever used in an astronomical site.

134

Million processors

2912

Printed circuits

5200

Cables of interface

20

Million welding points

2016

Antenna pairings which make the correlator capable of simultaneously running the interferometry