Radio telescopes could spot asteroids with unprecedented detail
They would need radar to do it
Astronomy is a passive science. Its practitioners usually earn their livings studying what they are given: light and other forms of radiation emitted by stars and nebulae, sometimes after it has bounced off other objects, such as planets. But there is an exception. A small but dedicated band of astronomers is not content with the views which nature offers. They choose, instead, to illuminate their targets artificially, by beaming microwaves at them and looking at the reflections. They are, in other words, observing by radar.
This article appeared in the Science & technology section of the print edition under the headline “Reflections of reality”
From the February 24th 2024 edition
Discover stories from this section and more in the list of contents
Explore the editionMore from Science & technology
How to reduce the risk of developing dementia
A healthy lifestyle can prevent or delay almost half of cases
GPT, Claude, Llama? How to tell which AI model is best
Beware model-makers marking their own homework
How America built an AI tool to predict Taliban attacks
“Raven Sentry” was a successful experiment in open-source intelligence
Gene-editing drugs are moving from lab to clinic at lightning speed
The promising treatments still face technical and economic hurdles, though
How Ukraine’s new tech foils Russian aerial attacks
It is pioneering acoustic detection, with surprising success
The deep sea is home to “dark oxygen”
Nodules on the seabed, rather than photosynthesis, are the source of the gas