Final yr, NASA’s DART mission made headlines after it efficiently smashed into the aspect of Dimorphos, the small orbiting companion of a bigger asteroid named Didymos. That deliberate impression measurable modified the orbit of Dimorphos, heralding a brand new chapter in humanity’s potential to defend itself from cosmic threats.
One small drawback: We’ve little or no concept of what these threats are and the place they could come from. Fortunately, NASA is hoping to alter that.
What number of near-Earth asteroids are there?
To place it mildly, rogue asteroids pose a significant risk to our survival right here on Earth. The biggest asteroids — these bigger than 0.6 miles (1 kilometer) throughout — are able to triggering extinction-level occasions on Earth. Nevertheless, giant asteroids are comparatively uncommon, hanging Earth solely each half-million years or so.
What’s extra regarding are the smaller, rather more quite a few asteroids which might be lower than 0.6 miles (1 km) throughout. Whereas these gained’t destroy a civilization, they may nonetheless take out a significant metropolis or two, or set off globe-spanning tsunami waves.
In 2005, the U.S. Congress determined that NASA ought to up its asteroid-detection recreation. Congress mandated that NASA determine, monitor, and characterize 90 p.c of near-Earth objects (NEOs) with a diameter better than 560 toes (140 meters). That’s so giant that really catastrophic issues would occur ought to such an asteroid strike Earth.
There was a deadline for the mandate, too: NASA was directed to perform the NEO-detection effort by 2020.
One catch, nonetheless. Regardless of the clear directive, Congress didn’t authorize any extra funding for NASA to really accomplish it.
NASA pushes for planetary protection
Because the 2020 deadline loomed, the intelligent of us at NASA acquired inventive. As an alternative of relying solely on ground-based surveys, which have been gradual and tough to fund, they prioritized new spaceflight missions, serving to them promote the idea of planetary protection to Congress.
It labored. Congress authorized the funding for DART a yr earlier than NASA even formally proposed it.
Together with DART additionally got here a repurposing of the defunct WISE spacecraft, which had been sitting dormant in orbit for a number of years. Now known as NEOWISE (for near-Earth Object Broad-field Infrared Survey Explorer), the rebranded instrument is now NASA’s go-to facility for locating potential threats to Earth.
