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

250

People work at ALMA in Chile, with a similar number of people working in the rest of the world

17

Different nationalities just among ALMA staff in Chile

100

Million US dollars are the average annual operating costs of ALMA on a global level

37.5%

Is the investment from partners ESO and NRAO in ALMA, and 25% is from NAOJ

176,000,000

M2 is the total surface area in concession from the Chilean government to ALMA for a 50-year period

250,000

US dollars is approximately what ALMA provides each year to the Chilean Ministry of National Heritage as lease for the concession

9

MW total installed capacity (turbines running with butane gas or diesel )

1.4

MW average consumption in the AOS (Chajnantor) and 1.2 MW in the OSF (camp)

15 – 20

KVA is the average electricity consumption of each antenna

11,000

Liters is the average monthly consumption of bottled water (in gallon containers)

2,042

M3 is the average monthly consumption of potable water purchased in San Pedro de Atacama

Astronomic Observations

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

+1500

Scientific publications

1800

Proposals for observations with ALMA are received on average each year

500

Projects observed each year

4000

Average observations hours in every cycle (a 1/3 part of what is requested)

43

Is the minimum number of antennas used for each baseline or main array observation

Antennas

66

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

6569

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

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). It is comprised of 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

10

Million US dollars was the average production cost for each antenna

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

197

Bases are on the Chajnantor Plateau for repositioning the 66 ALMA antennas based on observation needs

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

1

Second every three million years is the possible delay in the atomic watch (hydrogen maser) that allows ALMA to observe in synchronization with other telescopes

Transporters

700

Horsepower (500 kW) in the two diesel engines in each transporter

1800

Liters of diesel is consumed approximately when transporting an antenna from the OSF to the AOS

3000

Liter tank capacity

20

Km/h is the maximum speed of transporters and this is reduced to 12 km/h when transporting an antenna up to 5000 m

4

Operators are trained to handle the transporter

6

Months minimum is the time required to train operators to drive them