Short-period comets need roughly 200 years or less to complete one orbit, long-period comets take more than 200 years, and single-apparition comets are not bound to the sun, on orbits that take them out of the solar system, according to NASA.
Yes, you can invest in both an IRA and a 401k (or a Roth 401k and a Roth IRA) at the same time, or any combination of those accounts. And in some cases, based on the fees in your 401k, an IRA might actually be a better place to invest your money.
1 Higher contribution limits are permitted with a Roth Individual 401k than a Roth IRA. 2  For 2015 participants can contribute up to $18,000 to a Roth 401k ($24,000 if age 50 or older), but they can only contribute $5,500 ($6,500 if age 50 or older) into a Roth IRA.owever, a Roth Individual 401k allows much higher annual contribution amounts than a Roth IRA. In 2015 a Roth IRA has a $5,500 limit and $6,500 limit if age 50 or older. The 2015 contribution limit for the Roth Individual 401k is $18,000 and $24,000 if age 50 or older.