He argues that radar astronomy, which is used to probe things like asteroids and the surface of Venus, already gives off signals that could be picked up by aliens.

他认为，人类运用雷达天文学探测小行星和金星等天体，早已经发射出可以被外星智慧生物接收到的信号。

youdao

The technique has been highly successful in radio astronomy, and in both satellite and aircraft borne radar.

该技术在射电天文学、卫星雷达和机载雷达上均获得了巨大成功。

youdao

This article put a stress on the principle of Doppler effect and its application to astronomy, radar, transportation, medical treatment, etc.

本文重点讨论了多普勒效应的原理以及它在天文学、雷达、交通、医疗等方面的应用。

youdao

He argues that radar astronomy, which is used to probe things like asteroids and the surface of Venus, already gives off signals that could be picked up by aliens.

ECONOMIST: An argument over whether to send messages to aliens