Observations of neutral-current $\nu$ interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard ${}^8\mathrm{B}$ shape, the ${\nu }_e$ component of the ${}^8\mathrm{B}$ solar flux is ${\phi }_e{=1.76\mathrm{}}_{-0.05\mathrm{}}^{+0.05\mathrm{}}\left(\mathrm{stat}{)}_{-0.09\mathrm{}}^{+0.09\mathrm{}}\right(\mathrm{syst})\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$ for a kinetic energy threshold of 5 MeV. The non- ${\nu }_e$ component is ${\phi }_{\mu \tau }{=3.41\mathrm{}}_{-0.45\mathrm{}}^{+0.45\mathrm{}}\left(\mathrm{stat}{)}_{-0.45\mathrm{}}^{+0.48\mathrm{}}\right(\mathrm{syst})\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$, $5.3\sigma$ greater than zero, providing strong evidence for solar ${\nu }_e$ flavor transformation. The total flux measured with the NC reaction is ${\phi }_{\mathrm{NC}}{=5.09\mathrm{}}_{-0.43\mathrm{}}^{+0.44\mathrm{}}\left(\mathrm{stat}{)}_{-0.43\mathrm{}}^{+0.46\mathrm{}}\right(\mathrm{syst})\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$, consistent with solar models.

Solar neutrinos from ${}^8\mathrm{B}$ decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of ${\nu }_e$’s is measured by the CC reaction rate to be ${\phi }^{\mathrm{CC}}\left({\nu }_e\right)=1.75\mathrm{}\pm 0.07\left(\mathrm{stat}{)}_{-0.11\mathrm{}}^{+0.12\mathrm{}}\right(\mathrm{syst})\pm 0.05(\mathrm{theor})\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$. Comparison of ${\phi }^{\mathrm{CC}}\left({\nu }_e\right)$ to the Super-Kamiokande Collaboration’s precision value of the flux inferred from the ES reaction yields a $3.3\sigma$ difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- ${\nu }_e$ component in the solar flux. The total flux of active ${}^8\mathrm{B}$ neutrinos is determined to be $5.44\pm 0.99\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$.

The world atlas of zenith artificial night sky brightness is modelled with VIIRS DNB data and calibrated with more than 35,000 observations.

Earth’s artificially lit area is expanding at 2.2% per year, with existing lit areas brightening by 2.2% per year.

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted ${}^8\mathrm{B}$ spectrum, the night minus day rate is $14.0\%\pm 6.3{\%}_{-1.4\mathrm{}}^{+1.5\mathrm{}}\%$ of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the ${\nu }_e$ asymmetry is found to be $7.0\%\pm 4.9{\%}_{-1.2\mathrm{}}^{+1.3\mathrm{}}\%$. A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.

The Sudbury Neutrino Observatory has precisely determined the total active (${\nu }_x$) ${}^8\mathrm{B}$ solar neutrino flux without assumptions about the energy dependence of the ${\nu }_e$ survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be $5.21\pm 0.27\mathrm{(}\mathrm{stat}\mathrm{)}\pm 0.38\mathrm{(}\mathrm{syst}\mathrm{)}\times {10}^6{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$, in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields $\Delta m^2={7.1}_{-0.6}^{+1.2}\times {10}^{-5}{\mathrm{eV}}^2$ and $\theta ={32.5}_{-2.3}^{+2.4}$ degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.