On April 17 the Red Planet and Earth will line up on opposite sides of the sun, an event called solar conjunction. Other than not being able to see Mars because it’s hidden in the solar glare, the event has one real consequence for earthlings. We’ll explore that in a minute. Let’s just say that since the two planets now sit at opposite ends of the seesaw, Mars is about as far away as it gets, winking at Earth across a distance of 225.7 million miles. Compare that to 35 million when we’re closest.
That’s OUT THERE. Even light, traveling at 186,000 miles per second, takes 20 minutes to cross the gulf separating Earth from Mars. That means a 40 minute round trip for radio communications between the Curiosity and Opportunity rovers and mission control.
How would you like to get a feel for that distance? Understanding that time is precious, we’ll go easy on you by making the journey when Mars is closest to Earth. Normally it would take about 150 days to travel to the Red Planet using current technology. We’ll arrive quicker by accelerating to 3 times the speed of light. Even at that pace, you might be surprised how long it takes to arrive. Click HERE or on the image above to take the free journey. Bon voyage!
Let’s return to the consequences of a Mars solar conjunction. As described in this earlier blog, Mars’ close alignment with the sun does affect our ability to communicate with the Opportunity and Curiosity rovers. Signals sent from Earth pass directly along the sun’s line of sight en route to Mars where they could be corrupted by solar radiation storms and electrified particles in the sun’s corona.
It’s no big deal if bits of information go missing in a transmission from Curiosity, but if a bad command were sent from Earth, it might cause the robot to seize up or do damage to itself. To avoid potential problems, NASA has suspended communications for the remainder of April. Each day, Curiosity sends daily beeps to Earth telling mission control “I’m still here.”