Bengaluru-born astronomer at University of Arizona to lead NASA's $20 million mission

A small telescope; a question older than many of the instruments now used to study the heavens; and a scientist from Bengaluru at the head of the undertaking.

Dr Ramya Anche, an assistant research professor at the University of Arizona's Steward Observatory, has been selected as the principal investigator of NASA's PUFFINS mission - Polarimetry in the Ultraviolet to Find Features in INterStellar dust. NASA lists Anche as the mission's principal investigator under its Astrophysics Pioneers programme.

The mission has a $20 million award and is targeted for launch in 2030. At its centre will be a SmallSat carrying a telescope about 10 inches across. It will observe ultraviolet light from roughly 70 stars, seeking information about the very small grains of dust that lie between the stars.

The matter may sound modest - dust, after all. Yet astronomy has long known that the space between stars is not empty.

"PUFFINS will study the smallest grains of dust between the stars," Anche told The Hindu.

She described these particles as being roughly the size of a common cold virus; though nearly invisible to ordinary telescopes, they affect how starlight travels through the galaxy and are connected to the processes by which stars and planets form.

A TELESCOPE LOOKING AT WHAT ORDINARY LIGHT CANNOT TELL

PUFFINS will use ultraviolet spectropolarimetry - measuring the polarisation of ultraviolet light across wavelengths. The technique is not new in principle; but its use for this purpose from space has not been attempted in nearly three decades.

The mission's scientific interest lies in the smallest dust grains. According to the University of Arizona, PUFFINS will probe grains smaller than about 50 nanometres and examine how they align with the Milky Way's magnetic field. Their alignment leaves an imprint on starlight passing through the interstellar medium.

There is a longer history here.

Observations of interstellar dust polarisation date back decades; earlier ultraviolet observations were made by the Wisconsin Ultraviolet Photo-Polarization Experiment, which flew aboard the Space Shuttle in the early 1990s.

According to the PUFFINS science team, only about 30 stars and the interstellar medium before them have previously been examined in ultraviolet polarisation.

PUFFINS proposes to widen that view.

"The data it returns will fill a long-standing gap in our understanding of interstellar dust and by extension, the structure, and evolution of the universe," Anche told The Hindu.

The mission is a joint effort involving the University of Arizona, McDonald Observatory and researchers from several institutions.

Indian participation includes the Inter-University Centre for Astronomy and Astrophysics in Pune and the Indian Institute of Astrophysics in Bengaluru, according to the report and the mission's institutional material.

For Anche, the path to this point began in India. The Hindu reported that she grew up in Devanahalli, near Bengaluru, studied at institutions in the city and joined the Indian Institute of Astrophysics in 2012.

Her academic record later took her to a PhD at IIA and, in 2021, to Steward Observatory. Her work has centred on astronomical polarimetry, optical design, high-contrast imaging and space telescopes.

The selection itself came through NASA's competitive ROSES proposal process. Anche submitted the PUFFINS proposal while still a postdoctoral researcher, according to her account reported by The Hindu.

NASA's Astrophysics Pioneers programme is intended to give early-career scientists the opportunity to lead such missions.

There is, therefore, a second purpose to PUFFINS besides its scientific one.

The University of Arizona says graduate and undergraduate researchers are being involved from the beginning - in designing and developing the instrument, not merely in analysing the eventual data.

And there is a larger telescope waiting beyond it.

The Arizona team describes PUFFINS as a possible bridge to NASA's planned Habitable Worlds Observatory, for which ultraviolet spectropolarimetry may become relevant. The smaller mission, if successful, will provide observations that can help establish what such a future instrument might accomplish.

For now, the task is smaller; the question is not.

A telescope ten inches across will look towards distant stars and towards the dust between them - seeking to understand how some of the most ordinary particles in the galaxy participate in the making of stars and worlds.

And at its centre will be a scientist who began her journey near Bengaluru.