A giant mirror placed 10 light-years away would become the ultimate time machine. 
Because light takes time to travel, any image reflected back from that mirror would carry information from Earth’s past.
☄️ How close is that?
• Distance from Earth: ~20,000 miles (32,000 km)
• Closer than many geostationary satellites
• Visible to millions of people without a telescope
• One of the closest approaches of a large asteroid ever predicted
🌌 Will it hit Earth?
No.
Scientists have carefully tracked Apophis and confirmed that it poses no impact threat during its 2029 flyby.
Instead, it will provide a rare opportunity for astronomers to study a large asteroid up close.
🔭 A once-in-a-lifetime event
Apophis is about 1,100 feet (340 meters) wide and will appear as a bright moving point of light crossing the night sky.
Many people alive today may never see another asteroid of this size pass so close to Earth.
