Very Long Baseline Array

Ten big dishes look at space.

They work as one big team. This team is the longest in the world.

Each dish is very large. They are as tall as ten-story buildings.

They are also very heavy.

The dishes catch signals from far away. They save this info on hard drives. Then, they send it to a center.

Powerful computers look at the data. They fix small errors. They even fix errors from the spinning Earth.

These tools help us see the sky. It is a giant science team.

The Very Long Baseline Array is a team of ten radio telescopes.

These dishes work together as one big system. This is the longest system of its kind in the world. It uses interferometry, which is a way to combine signals. This helps scientists see better. Each dish is 25 meters wide. They are as tall as a ten-story building. Each dish weighs about 218 metric tons.

The dishes catch radio signals from space. They save this data on hard drives. These drives use atomic clocks to mark the time. Then, people carry the drives to New Mexico. Powerful computers there study the data. The computers fix small errors. They even fix errors from the Earth's rotation. The system was finished in May 1993. It cost about $85 million to build. Sometimes, other telescopes join the team. This makes a group called the High-Sensitivity Array. This group can see even more clearly.

The Very Long Baseline Array is a special team of ten radio telescopes.

It is part of the National Radio Astronomy Observatory. This system is the longest in the world. It uses a way of working called very long baseline interferometry. This helps scientists study the sky with great detail. The telescopes are operated from a center in Socorro, New Mexico. This center is called the Array Operations Center.

Each telescope works in a very specific way. Every receiver has a large dish that is 25 meters wide. These dishes are as tall as a ten-story building. Each one weighs about 218 metric tons.

The dishes catch radio signals from deep space. These signals are recorded on large hard disc drives. Atomic clocks are used to time-stamp the data perfectly. Then, the drives are moved to the Pete V. Domenici Science Operations Center. There, powerful computers process the signals. The computers fix errors caused by the Earth's rotation or shifts in the crust.

Building this huge system took many years of work. Construction began in February 1986. The project was finally finished in May 1993. The first big observation using all ten antennas happened on May 29, 1993. It cost about $85 million to build the whole array. Today, the National Science Foundation provides the funding. It costs about $10 million every year to keep it running.

The ten antennas are spread out across many different places. Some are in Hawaii at Mauna Kea. Others are in Washington at Brewster or in California at Owens Valley.

You can also find them in New Mexico, Arizona, and Iowa. Some antennas are even in the U.S. Virgin Islands at St. Croix. This wide spread allows the system to work as one giant tool. The longest distance between two antennas is about 8,000 kilometers.

Sometimes the VLBA joins with other telescopes to see even better. This group is called the High-Sensitivity Array. It can include the Green Bank Telescope in West Virginia. It can also include the Very Large Array in New Mexico. Even the Effelsberg radio telescope in Germany can join the team.

This makes the system five times more sensitive. It is like adding more eyes to a pair of glasses to see much more clearly.

The Very Long Baseline Array, or VLBA, is a sophisticated system of ten radio telescopes.

It functions as a single, massive instrument used for radio astronomy. This system is part of the National Radio Astronomy Observatory, which is managed by the NRAO. The VLBA is unique because it uses a technique called very long baseline interferometry. This method allows the antennas to work together as one giant detector. By combining signals from distant locations, scientists can study the universe with incredible detail. It is currently the longest system in the world that uses this specific interferometry method.

Each individual receiver in the array is a massive piece of engineering. Every station features a parabolic dish antenna that is 25 meters, or 82 feet, in diameter.

When pointed straight up, each antenna is about as tall as a ten-story building. These structures are incredibly heavy, weighing approximately 218 metric tons each. Each dish is paired with a dedicated control building. This building houses essential machinery like low-noise electronics and digital computers. It also contains data storage units and the machinery needed to point the antenna toward specific parts of the sky.

The process of capturing data is very precise and follows a strict sequence. First, the antennas catch radio signals from space. These signals are recorded onto a bank of hard disc drives that hold about one terabyte of data each. To ensure the data is accurate, atomic clocks are used to time-stamp the information. Once the drives are full, they are physically carried to the Pete V. Domenici Science Operations Center in Socorro, New Mexico. There, powerful digital computers perform signal processing to carry out the interferometry. These computers must also correct for the rotation of the Earth and tiny shifts in the Earth's crust to ensure the measurements remain perfect.

The VLBA is spread across a vast geographic area to maximize its capabilities. The ten antennas are located in several different places across the United States and the U.S. Virgin Islands. These locations include St. Croix, Hancock, North Liberty, Fort Davis, Los Alamos, Pie Town, Kitt Peak, Owens Valley, Brewster, and Mauna Kea.

Because the antennas are so far apart, the system can achieve a very long baseline. The longest distance between two antennas in the array is approximately 8,000 kilometers. This wide spread is what allows the array to act like a single, enormous telescope.

Building this complex scientific tool required significant time and investment. Construction of the VLBA began in February 1986 and was completed in May 1993. The very first astrometrical observation using all ten antennas took place on May 29, 1993. The total cost to build the entire array was about $85 million. Today, the National Science Foundation provides the funding for the project. It costs approximately $10 million every year to keep the array operating for scientists around the world.

Scientists use the VLBA to observe a wide range of radio frequencies. Most observations happen at wavelengths between three millimeters and 90 centimeters. This corresponds to frequencies ranging from 0.3 gigahertz to 96 gigahertz. Within this range, the VLBA can observe in eight different frequency bands. The array also observes in two narrow radio bands below one gigahertz. These specific bands are used to study spectral lines produced by bright maser emissions.

This flexibility allows the telescopes to study many different types of cosmic phenomena.

To increase its power, the VLBA can sometimes join forces with other telescopes. This configuration is known as the High-Sensitivity Array, or HSA. By including other major telescopes, the system's sensitivity can improve by a factor of five. The HSA can include the Green Bank Telescope in West Virginia and the Very Large Array in New Mexico. It can even include the Effelsberg radio telescope located in Germany. In the past, the Arecibo radio telescope in Puerto Rico was also part of this group before it collapsed. This connection to other global telescopes makes the VLBA part of a much larger, more powerful network for exploring the cosmos.