Just as the spaceship was traveling faster than light, you are traveling faster than snail-mail, so you beat some (or all) of your mailed selfies home. The day after your homecoming, the mail carrier delivers two of your pictures: one from the trip out, and a second from your trip back.
Ongoing research has shown that oral melatonin supplements can promote the dipping process. They can reduce nocturnal systolic blood pressure by about 6 mm/Hg, and diastolic pressure by 4 mm/Hg. Not surprisingly, the studies also indicate that melatonin improves sleep quality, which allows the body to relax more.
Periods of anxiety trigger the release of hormones that cause increased heart rate and decreased blood vessel diameter, both of which lead to increased blood pressure. The effect of stress on short term blood pressure can be dramatic, leading to mean arterial pressure increases of 30%-40%. These changes are short lived, though, with heart rate, blood vessel diameter, and blood pressure returning to normal as the hormones are eliminated. People with chronic anxiety disorders do not have chronic blood pressure increases as a result of their anxiety.