Astronomy Picture of the Day

Explanation: What's the closest active galaxy to planet Earth? That would be Centaurus A, catalogued as NGC 5128, which is only 12 million light-years distant. Forged in a collision of two otherwise normal galaxies, Centaurus A shows several distinctive features including a dark dust lane across its centre, outer shells of stars and gas, and jets of particles shooting out from a supermassive black hole at its centre. The featured image captures all of these in a composite series of visible light images totaling over 310 hours captured over the past 10 years with a homebuilt telescope operating in Auckland, New Zealand. The brightness of Cen A's centre from low-energy radio waves to high-energy gamma rays underlies its designation as an active galaxy.