Seeing something never before seen

MORE THAN 200 YEARS after British natural philosopher John Michell guessed the existence of big-massive objects from which even light could not escape, and 50 years after US theoretical physicist John Archibald Wheeler coined the term "black hole", humans got their first look at one on Wednesday evening, when the Event Horizon Telescope project made public the first photo of a black hole at a coordinated news conference jointly held in six cities on three continents. Humankind has been waiting for this for a long time, comments China Daily writer Zhang Zhouxiang:

Black holes are thought to be the biggest objects in the universe. For example, Sagittarius A*, the black hole located at the center of our Milky Way galaxy, is estimated to equal about 4 million suns in mass, with a diameter of about 44 million kilometers.

Yet they might be the most difficult to be seen by humankind, first because they are so far away from us. Sagittarius A* is 25,000 light years, or about 240,000 trillion kilometers, away from the Earth. To quote Gou Lijun, a senior astronomer at the National Astronomical Observatories, it is as difficult to observe Sagittarius A* as it is to observe an orange on the surface of the moon.