VLBA Marks 30 Years Pushing the Bounds of Science

On August 20, 2023, the National Radio Astronomy Observatory (NRAO) marked 30 years since the National Science Foundation’s Very Long Baseline Array (VLBA) had its inauguration ceremony in the high desert of New Mexico. In the three decades since, the VLBA has become not only one of the world’s most famous radio telescopes, but has also played a key role in radio astronomy across the country and the world. 

The VLBA is a critical tool for astronomy, where knowing distances is the basis for figuring out the mass, makeup, and movement of cosmic objects. High-precision observations are the VLBA’s greatest strength. With the VLBA’s accuracy, astronomers:

• Measure the spins and shapes of galaxies, including our Milky Way
• Collect cosmological distances to measure Dark Energy in the Universe
• Trace the movements of black holes and pulsars to learn their history and future
• Predict if and when galaxies will collide, including the Andromeda Galaxy with our Milky Way
• Provide the most accurate distances to stars
• Pinpoint the exact centers of planets in our Solar System
• Develop the celestial reference grid used by other telescope

In addition to these research contributions, the VLBA is utilized by the United States Naval Observatory (USNO). The USNO is a 50% funding partner with the NSF to operate the VLBA. The USNO makes use of VLBA data to develop and maintain the International Celestial Reference Frame which is used by all astronomers across the globe to define coordinates of the objects they study. The VLBA is the majority contributor of data to these reference frames.

The VLBA stations are located in areas with limited radio interference, and widely spread across the country. The distance between any two stations is known as their baseline. The longer the baseline, the better the angular resolution. The most widely separated antennas are at Mauna Kea in Hawaii and St. Croix in the U.S. Virgin Islands, which are 8,611 km apart. While each VLBA antenna is identical, each location is unique. With antennas located from New Hampshire to Washington, from Iowa to Hawaii, and within New Mexico in Los Alamos and Pie Town, the VLBA is truly America’s telescope.

The work of the VLBA is far from over. When asked about what’s to come for the VLBA, former VLBA Director and Deputy Assistant Director for VLBA Development Walter Brisken stated, “As new technology emerges, the VLBA’s capabilities continue to grow, and it remains an innovative instrument for radio astronomy.”